阅读说明：本技术 通信装置、中心设备及通信系统 (Communication device, center apparatus, and communication system ) 是由 刘永俊 张军平 于 2020-06-16 设计创作，主要内容包括：本申请提供一种通信装置、中心设备及通信系统,涉及通信技术领域,用于进行激光通信。该通信装置包括第一调制器和第一逆射腔镜；第一调制器,用于将第一数据调制到激光上,生成第一调制激光,第一调制激光承载有第一数据；第一逆射腔镜,用于向中心设备逆射第一调制激光。在激光通信的过程中,通信装置采用第一逆射腔镜逆射激光。第一逆射腔镜逆射的激光逆射到反射镜上,并由反射镜反射至其他通信装置的第二逆射腔镜。这样,第一逆射腔镜和第二逆射腔镜之间通过反射镜反射形成谐振,该通信装置和其他通信装置可以通过反射镜反射的激光进行通信,从而实现非视距通信。(The application provides a communication device, central equipment and a communication system, relates to the technical field of communication, and is used for laser communication. The communication device comprises a first modulator and a first retro-reflector; the first modulator is used for modulating first data onto laser to generate first modulated laser, and the first modulated laser carries the first data; and the first retro-reflection cavity mirror is used for retro-reflecting the first modulated laser to the central equipment. In the laser communication process, the communication device uses a first retro-reflection cavity mirror to retro-reflect laser. The laser reflected by the first retro-reflector is retro-reflected to the reflector and is reflected to the second retro-reflector of other communication devices by the reflector. Therefore, the first retro-reflection cavity mirror and the second retro-reflection cavity mirror are reflected by the reflecting mirror to form resonance, and the communication device and other communication devices can communicate through laser reflected by the reflecting mirror, so that non-line-of-sight communication is realized.)

1. A communications apparatus, comprising: a first modulator and a first retro-reflector;

the first modulator is configured to modulate first data onto laser light to generate first modulated laser light, where the first modulated laser light carries the first data;

and the first retro-reflection cavity mirror is used for retro-reflecting the first modulated laser to the central equipment.

2. The communications device of claim 1, further comprising: a first demodulator; the first demodulator is used for demodulating second modulated laser and acquiring second data carried by the second modulated laser; the second modulated laser is laser which is reversely reflected and transmitted by the first retro-reflector cavity mirror and comes from the central equipment; the second modulated laser carries the second data.

3. A communication device according to claim 1 or 2, wherein the first modulator is connected to the first retro-reflector; the first modulator is used for adjusting the reflecting state of the first reflecting cavity mirror according to the first data; the first retrodirective cavity mirror retrodirective irradiates laser with corresponding parameters according to the retrodirective state, and the laser with the corresponding parameters bears the first data.

4. The communication apparatus according to claim 1 or 2, characterized in that the communication apparatus further comprises: a first gain medium and a first pump source; the first gain medium generates laser under the action of the first pump source; the first pumping source is connected with the first gain medium; the first pump source is used for providing energy for the first gain medium;

the first modulator is connected with the first pumping source; the first modulator is used for adjusting the pumping power of the first pumping source according to the first data; the first gain medium outputs laser with corresponding power according to the pumping power of the first pumping source, and the laser with corresponding power carries the first data.

5. A communications apparatus, comprising: a second demodulator and a second retro-reflector;

the second retro-reflection cavity mirror is used for retro-reflecting and transmitting the first modulated laser from the central equipment; the first modulated laser carries first data;

the second demodulator is used for demodulating the first modulated laser transmitted by the second retro-reflector to acquire the first data carried by the first modulated laser.

6. The communications device of claim 5, further comprising: a second modulator;

the second modulator is used for modulating second data onto the laser to generate second modulated laser; the second modulated laser carries the second data;

and the second retro-reflection cavity mirror is also used for retro-reflecting the second modulated laser to the central equipment.

7. A communication device according to claim 6, wherein the second modulator is connected to the second retro-reflector; the second modulator is used for adjusting the reflecting state of the second reflecting cavity mirror according to the second data; and the second retrodirective cavity mirror retrodirective irradiates the laser with the corresponding parameters according to the retrodirective state, and the laser with the corresponding parameters bears the second data.

8. The communications device of claim 6, further comprising: a second gain medium and a second pump source; the second gain medium generates laser under the action of the second pump source; the second pumping source is connected with the second gain medium; the second pump source is used for providing energy for the second gain medium;

the second modulator is connected with the second pumping source; the second modulator is used for adjusting the pumping power of the second pumping source according to the second data; and the second gain medium outputs laser with corresponding power according to the pumping power of the second pumping source, and the laser with corresponding power carries the second data.

9. The communication device according to any of claims 1-8, wherein the communication device further comprises: a light shutter;

the optical shutter is positioned on one side of the retro-reflection cavity mirror for retro-reflecting laser, is in different states and can control the intensity of the laser entering the retro-reflection cavity mirror; the retroreflection cavity mirror is a first retroreflection cavity mirror or a second retroreflection cavity mirror.

10. The communication device according to any of claims 1-9, wherein the communication device further comprises: a filter disc;

the filter disc is positioned on one side of the retro-reflection cavity mirror for retro-reflecting laser; the filter disc is used for filtering target laser; the target laser and the laser with preset parameters have different parameters; wherein the parameters of the laser include one or more of: wavelength, polarization, and orbital angular momentum; the retroreflection cavity mirror is a first retroreflection cavity mirror or a second retroreflection cavity mirror.

11. The communication apparatus according to any one of claims 1 to 10, wherein the communication apparatus is further configured to transmit first indication information to the center device; the first indication information is used for indicating that the communication device requests to communicate.

12. The communication apparatus according to any of claims 1-11, further configured to receive second indication information from the central device; the second indication information is used for indicating the communication device to communicate within a preset communication time period;

and the communication device communicates with other communication devices in the preset communication time period.

13. The communications device of any of claims 1-12, wherein the communications device is further configured to adjust a rate at which the communications device transmits data based on the number of other communications devices.

14. A center device, comprising: a mirror, a third gain medium and a third pump source;

the third gain medium generates laser under the action of the third pump source; the third pumping source is connected with the third gain medium; the third pump source is used for providing energy for the third gain medium;

the reflector is configured to reflect the laser light modulated by the first communication device to the second communication device, where the modulated laser light carries the first data sent by the first communication device.

15. The hub apparatus of claim 14, wherein said mirror is transmissive to laser light; the center device further includes: a third demodulator; the third demodulator is positioned on one side of the reflector, which is used for transmitting laser;

the third demodulator is configured to demodulate third modulated laser and obtain third data carried by the third modulated laser; the third modulated laser is the reflector transmission laser; the third modulated laser carries third data.

16. The hub apparatus of claim 15, further comprising: a third retro-reflector;

the third retro-reflector is positioned on one side of the laser reflected by the reflector;

the third retro-reflection cavity mirror is used for transmitting and retro-reflecting laser.

17. The center apparatus of claim 16, wherein the third retro-reflector mirror is located on a side of the third gain medium facing a communication device, the communication device being at least one of the first communication device and the second communication device.

18. The hub apparatus of claim 16, wherein said third retro-reflector cavity mirror is located between said gain medium and said mirror.

19. The hub apparatus of any of claims 14-18, wherein the hub apparatus further comprises: a third modulator;

the third modulator is used for modulating fourth data onto laser to generate fourth modulated laser;

the center device is further configured to transmit the fourth modulated laser to the communication apparatus.

20. The hub apparatus of claim 19, wherein said third modulator is located on a side of said third gain medium facing a communication device.

21. The hub apparatus of claim 19, wherein said third modulator is located between said third gain medium and said mirror.

22. The hub apparatus of any of claims 19-21, wherein the third modulator is coupled to the third pump source, the third modulator configured to adjust a pump power of the pump source according to the fourth data; and the third gain medium outputs laser with corresponding power according to the pumping power of the pumping source, and the laser with corresponding power carries the fourth data.

23. The hub apparatus according to any of claims 15-21, wherein said hub apparatus is further configured to receive a first indication from a communication device; the first indication information is used for indicating that the communication device requests to communicate.

24. The hub device according to any of claims 19-23, wherein said hub device is further configured to send a second indication to said communication means; the second indication information is used for indicating the communication device to communicate within a preset communication time period.

25. The hub apparatus of any of claims 19-24, wherein the hub apparatus is further configured to adjust the pump power of the third pump source based on the number of communication devices accessing the hub apparatus.

26. A communication system, comprising: the system comprises a first communication device, a second communication device and central equipment; wherein the first communication device comprises a first retro-reflector cavity mirror and a first modulator; the second communication device comprises a second retro-reflector cavity mirror and a second demodulator; the central apparatus includes a mirror;

the first modulator is used for modulating first data onto laser to generate first modulated laser, and the first modulated laser carries the first data;

the first retro-reflection cavity mirror is used for retro-reflecting the first modulated laser to the reflecting mirror;

the reflector is used for reflecting the first modulated laser from the first retro-reflector to the second retro-reflector;

the second retro-reflector mirror is used for retro-reflecting and transmitting the first modulated laser from the reflector;

the second demodulator is used for demodulating the first modulated laser transmitted by the second retro-reflector to acquire the first data carried by the first modulated laser.

27. The communication system of claim 26, wherein the communication system further comprises: a gain medium and a pump source;

the gain medium generates laser under the action of the pumping source; the pumping source is connected with the gain medium; the pumping source is used for providing energy for the gain medium;

the gain medium is located in at least one of the center device and the first communication apparatus.

28. The communication system according to claim 26 or 27, wherein the second communication device further comprises a second modulator; the first communication device further comprises a first demodulator;

the second modulator is used for modulating second data onto the laser to generate second modulated laser; the second modulated laser carries the second data;

the second retro-reflection cavity mirror is also used for retro-reflecting the second modulated laser to the reflecting mirror;

the first retro-reflector is also used for retro-reflecting and transmitting the second modulated laser from the reflector;

the first demodulator is used for demodulating the second modulated laser and acquiring second data carried by the second modulated laser.

29. A communication system according to any of claims 26 to 28, wherein the mirror is transmissive to laser light; the center device further includes: a third demodulator; the third demodulator is positioned on one side of the reflector, which is used for transmitting laser;

the third demodulator is configured to demodulate third modulated laser and obtain third data carried by the third modulated laser; the third modulated laser is the reflector transmission laser; the third modulated laser carries third data.

30. The communication system according to claim 29, wherein the center device further comprises: a third retro-reflector;

the third retro-reflector is positioned on one side of the laser reflected by the reflector;

the third retro-reflection cavity mirror is used for transmitting and retro-reflecting laser.

31. The communication system according to any of claims 26-30, wherein the central device further comprises: a third modulator;

the third modulator is used for modulating fourth data onto laser to generate fourth modulated laser;

the center device is further configured to transmit the fourth modulated laser to at least one of the first communication apparatus and the second communication apparatus.

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication apparatus, a center device, and a communication system.

Background

In current laser communication, a communication device directly utilizes laser light emitted by a laser as a light source to carry data. In particular, the communication device (including the transmitting device and the receiving device) determines different laser parameters of the laser (e.g., intensity, polarization, orbital angular momentum, etc. of the laser) for characterizing different data. When communication is required, the transmitting device modulates the parameters of the laser light according to the data, and the modulated laser light carries the data. The transmitting device transmits the modulated laser light. And the receiving device receives the modulated laser from the sending device, demodulates the modulated laser according to the data represented by each laser parameter and acquires the data carried by the modulated laser. However, since laser light generally travels along a straight line in a propagation environment and the wavelength of the laser light is much smaller than that of a macroscopic object, in non-line-of-sight laser communication, communication between communication devices needs to be achieved through environmental reflection or scattering and the like, and since the capability of the environmental reflection or scattering of the laser light is very low, the transmission rate of the laser communication is generally low in the non-line-of-sight laser communication.

Disclosure of Invention

The application provides a communication device, central equipment and communication system, has solved among the prior art when adopting laser to carry out non-line of sight transmission, the lower problem of transmission rate.

In order to solve the technical problem, the following technical scheme is adopted in the application:

in a first aspect, a communication apparatus is provided, including: a first modulator and a first retro-reflector; the first modulator is used for modulating first data onto laser to generate first modulated laser, and the first modulated laser carries the first data; and the first retro-reflection cavity mirror is used for retro-reflecting the first modulated laser to the central equipment.

Based on the technical scheme, in the laser communication process, the communication device adopts the first retro-reflection cavity mirror to retro-reflect laser. The laser reflected by the first retro-reflector is retro-reflected to the reflector and is reflected to the second retro-reflector of other communication devices by the reflector. Therefore, the first retro-reflection cavity mirror and the second retro-reflection cavity mirror are reflected by the reflecting mirror to form resonance, and the communication device and other communication devices can communicate through laser reflected by the reflecting mirror, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

With reference to the first aspect, in one possible design, the communication device further includes: a first demodulator; the first demodulator is used for demodulating the second modulated laser and acquiring second data carried by the second modulated laser; the second modulated laser is laser which is reversely reflected and transmitted by the first retro-reflector cavity mirror and comes from the central equipment; the second modulated laser carries second data. Based on this, the communication apparatus can demodulate data by the first demodulator, thereby making the communication apparatus have a function of receiving data.

In a possible design in combination with the first aspect, the first modulator is connected to the first retro-reflector; the first modulator is used for adjusting the reflecting state of the first reflecting cavity mirror according to the first data; the first retrodirective cavity mirror retrodirective emits laser with corresponding parameters according to the retrodirective state, and the laser with the corresponding parameters bears first data. Based on this, the first modulator may modulate the data by adjusting the retro-reflective state of the first retro-reflector cavity mirror.

With reference to the first aspect, in one possible design, the communication device further includes: a first gain medium and a first pump source; the first gain medium generates laser under the action of a first pump source; the first pumping source is connected with the first gain medium; the first pump source is used to provide energy to the first gain medium. The first modulator is connected with the first pumping source; the first modulator is used for adjusting the pumping power of the first pumping source according to the first data; the first gain medium outputs laser light with corresponding power according to the pumping power of the first pumping source, and the laser light with corresponding power carries first data. Based on this, the first modulator can modulate the data by adjusting the pump power of the first pump source.

In a second aspect, a communication apparatus is provided, including: a second demodulator and a second retro-reflector; a second retroreflection cavity mirror for retroreflecting and transmitting the first modulated laser light from the center device; the first modulated laser carries first data; and the second demodulator is used for demodulating the first modulated laser transmitted by the second retro-reflector to acquire first data carried by the first modulated laser.

Based on the technical scheme, in the laser communication process, the communication device adopts the second retro-reflection cavity mirror to retro-reflect and transmit laser. For the retrodirective laser, the retrodirective laser can be retrodirective reflected on the reflector and reflected by the reflector to a retrodirective cavity mirror of other communication devices. Therefore, the first retro-reflection cavity mirror and the second retro-reflection cavity mirror are reflected by the reflecting mirror to form resonance, and the communication device and other communication devices can communicate through laser reflected by the reflecting mirror, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

In addition, the second retro-reflector transmits part of the laser light, so that the second demodulator can acquire the modulated laser light. The second modulator may acquire data carried by the modulated laser by demodulating the modulated laser.

In combination with the second aspect, in one possible design, the communication device further includes: a second modulator; the second modulator is used for modulating second data onto the laser to generate second modulated laser; the second modulated laser carries second data; and the second retro-reflection cavity mirror is also used for retro-reflecting the second modulated laser to the central equipment. Based on this, the communication device can modulate the data to be transmitted on the laser through the second modulator and transmit the modulated laser through the second retro-reflector. Thereby enabling the communication device to have a function of transmitting data.

In a possible design in combination with the second aspect described above, the second modulator is connected to the second retro-reflector; the second modulator is used for adjusting the reflecting state of the second reflecting cavity mirror according to the second data; the second retrodirective cavity mirror retrodirective irradiates the laser with the corresponding parameter according to the retrodirective state, and the laser with the corresponding parameter bears second data. Based on this, the second modulator may modulate the data by adjusting the retro-reflective state of the second retro-reflector cavity mirror.

In combination with the second aspect, in one possible design, the communication device further includes: a second gain medium and a second pump source; the second gain medium generates laser under the action of a second pump source; the second pumping source is connected with the second gain medium; the second pump source is used to energize the second gain medium. The second modulator is connected with a second pumping source; the second modulator is used for adjusting the pumping power of the second pumping source according to the second data; the second gain medium outputs laser light with corresponding power according to the pumping power of the second pumping source, and the laser light with corresponding power carries second data. Based on this, the second modulator can modulate the data by adjusting the pump power of the second pump source.

With reference to the first aspect or the second aspect, in one possible design, the communication device further includes: a light shutter; the optical shutter is positioned on one side of the retro-reflector cavity mirror for retro-reflecting the laser, is in different states and can control the intensity of the laser entering the retro-reflector cavity mirror; the retro-reflector is a first retro-reflector or a second retro-reflector. Based on this, when the optical shutter is in the state of transmitting laser light with certain intensity, the communication device can carry out resonance to transmit data; when the optical shutter is not transmitting any laser light, the communication device will not resonate, reducing the energy consumption of communication. In addition, in the case where different intensities of laser light represent different data, the modulator may also modulate the data onto the laser light by adjusting the light transmittance of the optical shutter.

With reference to the first aspect or the second aspect, in one possible design, the communication device further includes: a filter disc; the filter disc is positioned on one side of the back-reflection cavity mirror for back-reflection of laser; the filter disc is used for filtering target laser; the parameters of the target laser and the laser with preset parameters are different; wherein the parameters of the laser include one or more of: wavelength, polarization, and orbital angular momentum; the retro-reflector is a first retro-reflector or a second retro-reflector. Based on this, the communication device filters the target laser through the filter disc, so that the laser received by the communication device is the laser which needs to be received by the communication device, the interference of the target laser to the laser which needs to be demodulated by the communication device is reduced, and the target laser is prevented from influencing the demodulation performance of the demodulator.

With reference to the first aspect or the second aspect, in a possible design, the communication device is further configured to send first indication information to the central apparatus; the first indication information is used for indicating that the communication device requests to perform communication. Accordingly, when the communication device needs to perform communication, the communication device requests the center device to perform communication. The center device can reasonably schedule the communication devices to communicate according to the information such as the number of the communication devices in communication.

With reference to the first aspect or the second aspect, in a possible design, the communication device is further configured to receive second indication information from the central device; the second indication information is used for indicating the communication device to communicate in a preset communication time period; the communication device communicates with other communication devices within a preset communication period. Based on this, the communication apparatus performs communication within a preset communication period. Different communication devices may communicate during different communication periods to avoid communication interference with each other.

With reference to the first aspect or the second aspect, in one possible design, the communication device is further configured to adjust a rate at which the communication device transmits data according to the number of other communication devices. Since the pump power of the pump source is constant, when the number of communication devices to be communicated is excessive, the number of lasers in the communication system will increase, and the laser power between each corresponding pair of communication devices will decrease. At this time, the communication device transmits data at a low rate, so that the problem that data cannot be normally transmitted due to the fact that the laser power is too low can be avoided.

With reference to the first aspect or the second aspect, in a possible design, the communication device is further configured to receive third indication information from the central device; the third indication information is used for synchronizing the communication device; and the communication device carries out synchronization according to the third indication information. Based on this, the communication apparatus can perform synchronization between the communication apparatus and the center device according to the third indication information.

With reference to the first aspect or the second aspect, in one possible design, the light transmittance of the retro-reflector cavity mirror can be adjusted, and the retro-reflector cavity mirror is a first retro-reflector cavity mirror or a second retro-reflector cavity mirror. Based on this, the modulator can modulate data onto the laser by adjusting the light transmittance of the retro-reflector.

In combination with the first or second aspect, in one possible design, at least one of the first gain medium and the second gain medium includes a plurality of sub gain media; the wavelengths of the laser generated after the different sub gain mediums are excited and radiated are different. Therefore, the communication ranges covered by the laser beams with different wavelengths are different, and the communication devices in the coverage ranges communicate by adopting the laser beams with the corresponding wavelengths, so that the interference among the communication devices can be avoided. In addition, the laser with a plurality of wavelengths is adopted for communication, so that wavelength division multiplexing of the laser with different wavelengths can be realized, and the system capacity of a communication system is improved.

In a third aspect, a center device is provided, including: a mirror, a third gain medium and a third pump source; the third gain medium generates laser under the action of a third pump source; the third pumping source is connected with the third gain medium; the third pump source is used for providing energy for the third gain medium; and the reflector is used for reflecting the laser modulated by the first communication device to the second communication device, and the modulated laser carries the first data sent by the first communication device.

Based on the technical scheme, in the laser communication process, the central equipment reflects the laser modulated by the first communication device to the second communication device. Thus, the first retro-reflector of the first communication device and the second retro-reflector of the second communication device can be reflected by the reflector to form resonance, and the first communication device and the second communication device can communicate through laser reflected by the reflector, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

In a possible design in combination with the above third aspect, the mirror is transmissive to the laser light; the center device further includes: a third demodulator; the third demodulator is positioned on one side of the reflector for transmitting the laser; the third demodulator is used for demodulating the third modulated laser and acquiring third data carried by the third modulated laser; the third modulated laser is reflector transmission laser; the third modulated laser carries third data. Based on this, the center apparatus can demodulate data by the third demodulator, and thus, the center apparatus has a function of receiving data.

With reference to the third aspect, in one possible design, the center device further includes: a third retro-reflector; the third retro-reflector is positioned on one side of the reflector for reflecting the laser; the third retro-reflector is used for transmitting and retro-reflecting laser. Based on this, the central apparatus can be made to resonate with the retroreflective cavity mirror of the communication device through the third retroreflective cavity mirror. In this way, the center apparatus can realize the function of communicating with a single communication device.

With reference to the third aspect, in one possible design, the third retro-reflector cavity mirror is located on a side of the third gain medium facing the communication device, and the communication device is at least one of the first communication device and the second communication device. In this way, the third retro-reflector may resonate with the retro-reflector of the communication device towards which it is directed, so that the energy of the laser light transmitted between the two retro-reflectors is high.

In a possible design in combination with the above third aspect, the third retro-reflector mirror is located between the gain medium and the mirror. Therefore, the third retro-reflector can form resonance with the retro-reflector of all communication devices in the reflecting range of the reflector, and the coverage range of the third retro-reflector is enlarged.

With reference to the third aspect, in one possible design, the center device further includes: a third modulator; the third modulator is used for modulating the fourth data to the laser to generate fourth modulated laser; the center device is also used for sending the fourth modulated laser to the communication device. Based on this, the center device can modulate data onto the laser light through the third modulator, and thus, the center device has a function of transmitting data.

In combination with the above third aspect, in one possible design, the third modulator is located on a side of the third gain medium facing the communication device. Based on this, the third modulator can modulate data into the laser light by adjusting laser parameters of the laser light generated by the stimulated emission of the third gain medium.

In one possible design in combination with the above third aspect, the third modulator is located between the third gain medium and the mirror. Based on this, the third modulator can modulate data into the laser light by adjusting the reflection state of the mirror.

With reference to the third aspect, in one possible design, a third modulator is connected to the third pump source, and the third modulator is configured to adjust the pump power of the pump source according to fourth data; the third gain medium outputs laser with corresponding power according to the pumping power of the pumping source, and the laser with corresponding power carries fourth data. Based on this, the third modulator can modulate data into the laser by adjusting the pump power of the third pump source.

With reference to the third aspect, in one possible design, the center device is further configured to receive first indication information from the communication apparatus; the first indication information is used for indicating that the communication device requests to perform communication. Based on this, the center device can appropriately schedule the communication devices to communicate according to information such as the number of communication devices that are communicating.

With reference to the third aspect, in a possible design, the center device is further configured to send second indication information to the communication apparatus; the second indication information is used for indicating the communication device to communicate in the preset communication time period. Based on this, the center device can allocate a corresponding communication time period to each pair of communication devices according to the number of the communication devices and the like, so as to avoid communication interference between a plurality of pairs of communication devices caused by simultaneous communication.

With reference to the third aspect, in one possible design, the center device is further configured to send third indication information to the communication apparatus; the third indication information is used for synchronizing the communication apparatus. Based on this, the center apparatus can realize synchronization between the communication device and the center apparatus according to the third indication information.

In a possible design in combination with the third aspect, the central apparatus is further configured to adjust the pump power of the third pump source according to the number of communication devices accessing the central apparatus. Based on this, when the number of the communication devices accessing the center equipment is large, the center equipment correspondingly increases the pumping power of the third pumping source, so as to ensure that each communication device uses laser with relatively stable power to perform communication.

In combination with the above third aspect, in one possible design, the light transmittance of any one or more of the mirror and the third retro-reflector can be adjusted. Based on this, the modulator can modulate data onto the laser by adjusting the light transmittance of the mirror and/or the retro-reflector.

With reference to the third aspect, in one possible design, the third gain medium includes a plurality of sub gain media; the wavelengths of the laser generated after the different sub gain mediums are excited and radiated are different. Therefore, the communication ranges covered by the laser beams with different wavelengths are different, and the communication devices in the coverage ranges communicate by adopting the laser beams with the corresponding wavelengths, so that the interference among the communication devices can be avoided. In addition, the laser with a plurality of wavelengths is adopted for communication, so that wavelength division multiplexing of the laser with different wavelengths can be realized, and the system capacity of a communication system is improved.

In a fourth aspect, a communication system is provided, including: the system comprises a first communication device, a second communication device and central equipment; wherein the first communication device comprises a first retro-reflector cavity mirror and a first modulator; the second communication device comprises a second retro-reflector cavity mirror and a second demodulator; the central apparatus includes a mirror; the first modulator is used for modulating first data onto laser to generate first modulated laser, and the first modulated laser carries the first data; the first back reflection cavity mirror is used for back reflecting the first modulated laser to the reflector; the reflecting mirror is used for reflecting the first modulated laser from the first retro-reflector to the second retro-reflector; a second retroreflection cavity mirror for retroreflecting and transmitting the first modulated laser light from the mirror; and the second demodulator is used for demodulating the first modulated laser transmitted by the second retro-reflector to acquire first data carried by the first modulated laser.

Based on the technical scheme, the first retro-reflection cavity mirror of the first communication device, the second retro-reflection cavity mirror of the second communication device and the reflector of the central device form an outer resonant cavity of the laser together. The first communication device and the second communication device can communicate through the laser reflected by the reflector, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

With reference to the fourth aspect, in one possible design, the communication system further includes: a gain medium and a pump source; the gain medium generates laser under the action of a pumping source; the pumping source is connected with the gain medium; the pumping source is used for providing energy for the gain medium; the gain medium is located in at least one of the center device and the first communication apparatus. Based on this, when the gain medium is located in the center device, the communication device does not need to supply energy for generating laser light, thereby greatly reducing the power consumption of the communication device. When the gain medium is located in the communication device, the communication device can flexibly adjust the pumping power of the pumping source of the gain medium to perform communication so as to maintain the stability of laser power, or modulate data to laser by adjusting the pumping power of the pumping source, and the like.

With reference to the fourth aspect, in one possible design, the second communication device further includes a second modulator; the first communication device further comprises a first demodulator; the second modulator is used for modulating second data onto the laser to generate second modulated laser; the second modulated laser carries second data; the second retro-reflection cavity mirror is also used for retro-reflecting the second modulated laser to the reflector; the first retro-reflection cavity mirror is also used for retro-reflecting and transmitting the second modulated laser from the reflecting mirror; the first demodulator is used for demodulating the second modulated laser and acquiring second data carried by the second modulated laser.

In combination with the above fourth aspect, in one possible design, the gain medium may be located in the second communication device.

In a possible design in combination with the above fourth aspect, the mirror is capable of transmitting laser light; the center device further includes: a third demodulator; the third demodulator is positioned on one side of the reflector for transmitting the laser; the third demodulator is used for demodulating the third modulated laser and acquiring third data carried by the third modulated laser; the third modulated laser is reflector transmission laser; the third modulated laser carries third data.

With reference to the fourth aspect, in one possible design, the center device further includes: a third retro-reflector; the third retro-reflector is positioned on one side of the reflector for reflecting the laser; the third retro-reflector is used for transmitting and retro-reflecting laser.

In a possible design in combination with the above fourth aspect, the third retro-reflector cavity mirror is located at a side of the gain medium facing the first retro-reflector cavity mirror and/or the second retro-reflector cavity mirror.

In a possible design in combination with the above fourth aspect, the third retro-reflector mirror is located between the gain medium and the mirror.

With reference to the fourth aspect, in one possible design, the center device further includes: a third modulator; the third modulator is used for modulating the fourth data to the laser to generate fourth modulated laser; the center device is further configured to transmit the fourth modulated laser to at least one of the first communication device and the second communication device.

In a possible design in combination with the above fourth aspect, the third modulator is located on a side of the gain medium facing the first and/or second retro-reflector cavity mirror.

In a possible design in combination with the above fourth aspect, the third modulator is located between the gain medium and the mirror.

With reference to the fourth aspect, in one possible design, a communication device of a communication system includes: a light shutter; the communication device is at least one of a first communication device and a second communication device; the optical shutter is positioned on one side of the target retro-reflector cavity mirror for retro-reflecting laser, is in different states and can control the intensity of the laser entering the retro-reflector cavity mirror; the retrodirective cavity mirror is a retrodirective cavity mirror in the communication device.

With reference to the fourth aspect, in one possible design, a communication device of a communication system includes: a filter disc; the communication device is at least one of a first communication device and a second communication device; the filter disc is positioned on one side of the back-reflection cavity mirror for back-reflection of laser; the filter disc is used for filtering target laser; the parameters of the target laser and the laser with preset parameters are different; wherein the parameters of the laser are one or more of the following: wavelength, polarization, and orbital angular momentum; the retrodirective cavity mirror is a retrodirective cavity mirror in the communication device.

In combination with the above fourth aspect, in one possible design, the gain medium includes a first gain medium; the pump source comprises a first pump source, and the first gain medium is located in the first communication device. The first gain medium generates laser under the action of a first pump source; the first pumping source is connected with the first gain medium; the first pump source is used to provide energy to the first gain medium. The first modulator is connected with the first pumping source; the first modulator is used for adjusting the pumping power of the first pumping source according to the first data; the first gain medium outputs laser light with corresponding power according to the pumping power of the first pumping source, and the laser light with corresponding power carries first data.

With reference to the fourth aspect, in one possible design, the gain medium further includes a second gain medium; the pump source further includes a second pump source, and the second gain medium is located in the second communication device. The second gain medium generates laser under the action of a second pump source; the second pumping source is connected with the second gain medium; the second pump source is used to energize the second gain medium. The second modulator is connected with a second pumping source; the second modulator is used for adjusting the pumping power of the second pumping source according to the second data; the second gain medium outputs laser light with corresponding power according to the pumping power of the second pumping source, and the laser light with corresponding power carries second data.

With reference to the fourth aspect, in one possible design, the gain medium further includes a third gain medium; the pump source further includes a third pump source, the third gain medium being located in the central apparatus. The third gain medium generates laser under the action of a third pump source; the third pumping source is connected with the third gain medium; the third pump source is used to energize the third gain medium. The third modulator is connected with a third pump source and used for adjusting the pump power of the pump source according to fourth data; the third gain medium outputs laser with corresponding power according to the pumping power of the pumping source, and the laser with corresponding power carries fourth data.

In a possible design in combination with the above fourth aspect, the first modulator is connected to the first retro-reflector; the first modulator is used for adjusting the reflecting state of the first reflecting cavity mirror according to the first data; the first retrodirective cavity mirror retrodirective irradiates the laser with the corresponding parameters according to the retrodirective state, and the laser with the corresponding parameters bears the first data.

In a possible design in combination with the above fourth aspect, the second modulator is connected to the second retro-reflector; the second modulator is used for adjusting the reflecting state of the second reflecting cavity mirror according to the second data; the second retrodirective cavity mirror retrodirective irradiates the laser with the corresponding parameter according to the retrodirective state, and the laser with the corresponding parameter bears the second data.

In combination with the above fourth aspect, in one possible design, the light transmittance of any one or more of the mirror, the first retro-reflector, the second retro-reflector, and the third retro-reflector can be adjusted.

With reference to the fourth aspect, in one possible design, one or more gain mediums among the gain medium, the first gain medium, the second gain medium, and the third gain medium include a plurality of sub gain mediums; the wavelengths of the laser generated after the different sub gain mediums are excited and radiated are different.

It should be appreciated that the description of technical features, solutions, benefits, or similar language in this application does not imply that all of the features and advantages may be realized in any single embodiment. Rather, it is to be understood that the description of a feature or advantage is intended to include the specific features, aspects or advantages in at least one embodiment. Therefore, the descriptions of technical features, technical solutions or advantages in the present specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and advantages described in the present embodiments may also be combined in any suitable manner. One skilled in the relevant art will recognize that an embodiment may be practiced without one or more of the specific features, aspects, or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments.

Drawings

Fig. 1 is a schematic diagram of a laser in the prior art according to an embodiment of the present disclosure;

fig. 2 is a system architecture diagram of a laser communication system according to an embodiment of the present disclosure;

fig. 3 is a system architecture diagram of another laser communication system provided by an embodiment of the present application;

fig. 4 is a schematic structural diagram of an external cavity laser provided in an embodiment of the present application;

fig. 5 is a schematic structural diagram of an external cavity laser with multiple partial lenses according to an embodiment of the present disclosure;

fig. 6 is a system architecture diagram of a communication system according to an embodiment of the present application;

fig. 7 is a schematic diagram illustrating a propagation direction of laser light in a communication system according to an embodiment of the present disclosure;

fig. 8a is a system architecture diagram of another communication system provided in an embodiment of the present application;

fig. 8b is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 9 is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 10 is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 11 is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 12a is a system architecture diagram of another communication system provided in an embodiment of the present application;

fig. 12b is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 12c is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 13 is a schematic distribution diagram of a time cycle and a communication period provided in an embodiment of the present application;

fig. 14 is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 15 is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 16 is a system architecture diagram of another communication system provided by an embodiment of the present application;

fig. 17 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 18 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 19 is a schematic structural diagram of a center device according to an embodiment of the present application.

Detailed Description

In the description of this application, "/" means "or" unless otherwise stated, for example, A/B may mean A or B. "and/or" herein is merely an association describing an associated object, and means that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. Further, "at least one" means one or more, "a plurality" means two or more. The terms "first", "second", and the like do not necessarily limit the number and execution order, and the terms "first", "second", and the like do not necessarily limit the difference.

It is noted that, in the present application, words such as "exemplary" or "for example" are used to mean exemplary, illustrative, or descriptive. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

The communication device described in the embodiments of the present application may be a terminal device, a communication chip, a communication module, a communication unit, or the like. When the communication apparatus is a communication chip, a communication module or a communication unit, the communication apparatus may be coupled with a terminal device to implement all or part of the functions of the communication apparatus.

The central device described in the embodiments of the present application may be a network device.

The communication system in the embodiment of the present application includes, but is not limited to, a Long Term Evolution (LTE) system, a fifth generation (5G) system, a New Radio (NR) system, a Wireless Local Area Network (WLAN) system, and a future evolution system or a multiple communication convergence system. For example, the method provided by the embodiment of the present application may be specifically applied to an evolved-terrestrial radio access network (E-UTRAN) and a next generation radio access network (NG-RAN) system.

The network device in the embodiment of the present application is an entity for transmitting a signal, or receiving a signal, or transmitting a signal and receiving a signal on a network side. The network device may be a device deployed in a Radio Access Network (RAN) and providing a wireless communication function for a terminal device, and may be, for example, a Transmission Reception Point (TRP), a base station (e.g., an evolved NodeB (eNB or eNodeB)), a next generation base station (gNB), a next generation eNB (ng-eNB), and the like), various control nodes (e.g., a network controller, a radio controller (e.g., a radio controller in a Cloud Radio Access Network (CRAN) scenario)), a roadside unit (RSU), and the like. Specifically, the network device may be a macro base station, a micro base station (also referred to as a small station), a relay station, an Access Point (AP), or the like in various forms, and may also be an antenna panel of the base station. The control node may be connected to a plurality of base stations, and configure resources for a plurality of terminal devices under the coverage of the plurality of base stations. In systems using different Radio Access Technologies (RATs), the names of devices that function as base stations may differ. For example, the LTE system may be referred to as eNB or eNodeB, and the 5G system or NR system may be referred to as gNB, and the application does not limit the specific names of the base stations. The network device may also be a network device in a Public Land Mobile Network (PLMN) for future evolution, and the like.

The terminal device in the embodiment of the present application is an entity for receiving a signal, or transmitting a signal, or both receiving a signal and transmitting a signal, at a user side. The terminal device is used to provide one or more of voice services and data connectivity services to the user. A terminal device may also be referred to as a User Equipment (UE), a terminal, an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user equipment. The terminal device may be a vehicle networking (V2X) device, such as a smart car (smart car or interactive car), a digital car (digital car), an unmanned car (unmanned car or drive car or pilot car or auto-mobile), an automatic car (self-driving car or auto-mobile car), a pure electric car (pure EV or Battery EV), a hybrid electric car (HEV), a Range Extended EV (REEV), a plug-in hybrid EV, a new energy vehicle (PHEV), and the like. The end device may also be a device-to-device (D2D) device, such as an electric meter, water meter, etc. The terminal device may also be a Mobile Station (MS), a subscriber unit (subscriber unit), a drone, an internet of things (IoT) device, a station in a WLAN (station, ST), a cellular phone (cellular phone), a smart phone (smart phone), a cordless phone, a wireless data card, a tablet, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a laptop computer (laptop computer), a Machine Type Communication (MTC) terminal, a handheld device with wireless communication capability, a computing device, or other processing device connected to a wireless modem, a vehicle mounted device, a wearable device (also referred to as a wearable smart device). The terminal device may also be a terminal device in a next generation communication system, for example, a terminal device in a 5G system or a terminal device in a PLMN for future evolution, a terminal device in an NR system, etc.

In order to make the present application clearer, a brief description of some concepts related to the present application will be given first.

1. Laser device

The basic operating principle of a laser is stimulated radiation. Stimulated emission refers to: under the excitation of external incident photons, atoms in the excited state transition to a low energy level and radiate photons. These radiated photons are the same as the incident photons in frequency, direction, phase and polarization state. In this way, the substance in the laser can emit light with greater intensity through stimulated radiation.

The laser mainly comprises three parts, which are respectively: a pump source, a gain medium and a resonant cavity. Which will be described in detail below.

1.1 gain medium

The gain medium is the above-mentioned substance in the excited state, and the gain medium is mainly used for performing excited radiation, generating light with the same frequency, direction, phase and polarization state as the incident photon, and performing gain on the incident light.

1.2 Pump Source

The pumping source is used for providing energy for the gain medium, and atoms in the gain medium at a low energy level are lifted to a high energy level, so that the energy level of the particles is reversed. By the aid of the pumping source, atoms in the gain medium, which are transited to low energy levels due to stimulated radiation, can be promoted to high energy levels again, and accordingly recycling of the gain medium is achieved. In the energy input region of the pump source, atoms of low energy level are raised to high energy level, and therefore, the energy input region of the pump source is also called a population inversion region.

Current pump sources can pump by electrical, optical, or chemical forms of energy.

1.3 resonant cavity

The resonant cavity is generally composed of two mirrors, one of which is a total reflection mirror; the other surface is a reflector with partial transmission function, also called output mirror. The laser outputs laser light through the output mirror.

The gain medium is positioned between the two reflectors of the resonant cavity, and light generated by the incident light and the stimulated radiation is reflected between the two reflectors, so that the incident light can be continuously provided for the gain medium to carry out the stimulated radiation. Thereby achieving continuous amplification of incident light. In addition, only the incident light parallel to the axes of the two mirrors will be reflected back and forth, and the light not parallel to the axes will exceed the coverage of the mirrors and cannot be reflected after one or more reflections. Thus, the laser emitted by the laser has better directivity.

As shown in fig. 1, the working schematic diagram of a laser is shown, in which a pump source is used to provide energy for a gain medium, the gain medium is used to perform stimulated radiation after being irradiated by incident light, so as to amplify the incident light, and a part of light generated by the stimulated radiation is sent out through a partially transmissive mirror to form output laser; and one part of the laser beam is reflected by the partially-transmitted reflector, resonance is formed between the partially-transmitted reflector and the total reflector, and the gain medium is subjected to stimulated radiation continuously and outputs laser continuously.

2. Laser communication

Laser communication is one form of wireless optical communication. Wireless optical communication refers to a technology of carrying information using light waves and transmitting, propagating, and receiving in an open space. Due to the high frequency and the extremely wide frequency spectrum of light (including infrared light, visible light, ultraviolet light and the like), wireless optical communication has a great bandwidth potential. To achieve high bandwidth communication, a high bandwidth light source or modulator and a high bandwidth detector or demodulator are required.

The laser has the characteristics of strong monochromaticity, good coherence, good directivity and the like, the bandwidth directly modulated by the laser is often higher than that of other light sources such as an LED and the like, and the laser can also be used as the input of a high-speed external modulator, so the wireless laser communication is a common implementation means of high-bandwidth wireless optical communication.

In the process of communication by using laser, the laser emitted by the laser is directly used as a light source to carry data to be sent. When data is modulated by laser light, the following two modulation methods, i.e., method 1 and method 2, are included, and method 1 and method 2 will be described in detail below.

Mode 1

As shown in fig. 2, in mode 1, the modulator is located before the laser.

When data is transmitted, the data is first input to a modulator, and the modulator modulates the data onto the laser by adjusting the operating parameters of the laser and the like according to the input data. For example, the modulator generates a corresponding electrical signal according to the data, and controls parameters of laser output by the laser through the electrical signal, so as to modulate the data onto the laser, or the modulator modulates the data through encoding, modulation, upsampling, and the like. Modulated laser light (i.e., an optical signal of data to be transmitted) is generated. When receiving data, the receiving communication device receives the modulated laser, and demodulates the modulated laser through the demodulator to obtain data carried by the laser.

Mode 2

As shown in fig. 3, in mode 2, the modulator is located after the laser.

When data is sent, laser is firstly emitted to a modulator through a laser, and the modulator comprises two paths of inputs, wherein one path is the laser emitted by the laser, and the other path is the input data to be sent. The modulator modulates parameters of the laser according to data to be transmitted, and generates the modulated laser to output the laser with different laser parameters, wherein the different laser parameters can represent different data information. When receiving data, the receiving communication device receives the modulated laser, and demodulates the modulated laser through the demodulator to obtain data carried by the laser.

3. External resonant cavity laser

An external cavity laser is a laser in which a partially transmissive mirror in the cavity is separated from the rest of the laser. As shown in fig. 4, the partially transmissive mirror is disposed at the communication device for the structural schematic diagram of the external cavity laser, so that when there is a shielding object between the total reflection mirror and the partially transmissive mirror, the resonance condition of the laser will be destroyed, and at this time, the laser will not generate laser output. Thereby enhancing the safety of laser transmission.

As shown in fig. 5, in an external cavity laser, a plurality of partially transmissive mirrors may be provided. Each partially transmissive mirror of the plurality of partially transmissive mirrors may form a resonant cavity with the total reflective mirror, thereby simultaneously generating multiple laser outputs.

It should be noted that after the external cavity laser starts operating, the laser light generated by the gain medium can propagate to the mirror surface in each direction of the partially transmissive mirror. But only the laser light propagating the partially transmissive mirror can form a resonance in the communication system, eventually forming a stably transmitting laser light. The laser light propagating to other directions will be weakened continuously because of the failure to form resonance, and therefore, the laser light with stable transmission cannot be formed.

4. Reflection and reflection mirror

The phenomenon of light changing direction of propagation at the interface of two substances and returning to the original substance is called light reflection. In the light reflection process, the reflected light ray, the incident light ray and the normal are on the same plane; the reflected light and the incident light are distributed on two sides of the normal; the angle of reflection is equal to the angle of incidence.

A mirror is an optical device that works using the law of reflection, reflecting light back to the original material. The reflecting mirror can be divided into a plane reflecting mirror, a spherical reflecting mirror and an aspheric reflecting mirror according to the shapes. The reflecting mirror can be divided into a full reflecting mirror and a half reflecting mirror according to the reflecting degree. The total reflection mirror can totally reflect the light back to the original substance. The half mirror is capable of reflecting a portion of the light back to the original material and transmitting a portion of the light through the mirror.

5. Transmission through

Transmission is the phenomenon of the emergence of incident light after it has passed through an object by refraction.

6. Retro-reflection and retro-reflection endoscope

Back reflection is a phenomenon in which light changes its propagation direction at the interface between two substances and returns to the original substance in the direction opposite to the original propagation direction.

A retrodirective cavity mirror refers to an optical device that is capable of retrodirective light, such that the light propagates in a direction opposite to the original propagation direction. In the embodiment of the present application, a cube-corner mirror, a cat-eye retroreflector, a super-surface retroreflector, and the like can be used as the retroreflection mirror.

In order to solve the problem that the communication rate of laser communication in non-line-of-sight communication is low in the prior art, the embodiment of the application provides a communication system.

As shown in fig. 6, the communication system includes: the device comprises a first communication device, a second communication device and a center device.

Wherein the first communication device comprises a first retro-reflector cavity mirror and a first modulator; the second communication device comprises a second retro-reflector cavity mirror and a second demodulator; the central apparatus includes a mirror.

The first modulator is used for modulating the first data onto the laser to generate first modulated laser, and the first modulated laser carries the first data.

And the first retro-reflection cavity mirror is used for retro-reflecting the first modulated laser to the reflector.

And the reflecting mirror is used for reflecting the first modulated laser from the first retro-reflector to the second retro-reflector.

And a second retro-reflector for retro-reflecting and transmitting the first modulated laser light from the reflector.

And the second demodulator is used for demodulating the first modulated laser transmitted by the second retro-reflector to acquire first data carried by the first modulated laser.

It should be noted that the first communication device is a device for transmitting data, and the second communication device is a device for receiving data.

The communication system also includes a gain medium and a pump source.

A gain medium and a pump source; the gain medium generates laser under the action of a pumping source; the pumping source is connected with the gain medium; a pump source is used to provide energy to the gain medium. The gain medium is located in at least one of the center device and the first communication apparatus.

Based on the above technical solution, the embodiment of the present application provides a communication system. The first retro-reflector, the second retro-reflector and the reflector form a reflecting external resonant cavity. The first retro-reflector and the second retro-reflector are reflected by the reflector to form resonance, so that non-line-of-sight communication is realized.

Further, in the related art, since the beam of the laser light is narrow, it is difficult to perform initial alignment and tracking when two communication apparatuses communicate. And because the energy of the laser is concentrated, the potential safety hazard of the laser is large (for example, the direct irradiation of the human body may cause harm to the human body).

In the embodiment of the application, the laser reversely reflected by the first reverse cavity mirror can cover a larger area (marked as the coverage area of the first communication device) after being reflected by the reflecting mirror, and the communication devices in the coverage area of the first communication device can communicate with the first communication device, so that the difficulty of initial alignment and tracking of the communication devices can be greatly reduced. In addition, in the embodiment of the present application, a structure of reflecting the external cavity laser is adopted, when any one of the lines through which light propagates in the first communication device, the central device, and the second communication device is shielded, the resonance condition of the laser is damaged, and the laser output is immediately stopped, so that the safety of laser transmission is increased.

In one possible design, as shown in fig. 6, the communication system has the following positional relationship between the devices: in the communication system, one surface of the reflecting mirror for reflecting the laser light is opposite to one surface of the retroreflection cavity mirror (including the first retroreflection cavity mirror and the second retroreflection cavity mirror) for retroreflecting the laser light. The gain medium is located in the central device between the mirror and the retro-reflector. Therefore, the laser in the specific direction generated after the gain medium is subjected to stimulated radiation can be reflected back and forth among the reflector, the first retro-reflector and the second retro-reflector to form resonance, and therefore the laser with high intensity, good monochromaticity and good directivity is generated. The pump source is connected with the gain medium and used for providing energy for the stimulated radiation of the gain medium. The first modulator is positioned on one side of the first retro-reflection cavity mirror for retro-reflecting laser. The second demodulator is positioned on one side of the second retro-reflector cavity mirror, which is used for transmitting laser. The second retro-reflector is positioned in the covering range of the laser reflected by the first retro-reflector and the reflector. According to the reversibility of light, the first retro-reflector is also positioned in the coverage range of the laser which is retro-reflected by the second retro-reflector and reflected by the reflector.

The laser beam-transmitting side refers to a direction in which the laser beam is emitted after passing through a medium (a mirror, a first retrodirective mirror, a second retrodirective mirror, or the like).

It should be noted that, for the sake of easy understanding, the positional relationship of each device in the communication system is described above by taking fig. 7 as an example. In the actual implementation process of the embodiment of the present application, the position relationship of each device may be adjusted accordingly. For example, the gain medium may also be in a communication device; the first modulator is connected with the first retro-reflector, and the position of the first modulator can be set at will. The present application is not intended to be limited to the particular locations of the various components.

As shown in fig. 7, the propagation direction of the laser light in the communication system is shown.

And I, after the gain medium is excited to radiate to generate laser, one laser beam is incident on the first back reflector along the propagation path 1. The laser beam is transmitted along a specific direction in all directions generated by the stimulated radiation of the gain medium. The laser light propagating in the specific direction can form resonance among the first retro-reflector, the mirror and the second retro-reflector.

And II, the first retro-reflector retro-reflects the laser so that the laser is incident on the reflector along the propagation path 2. The propagation paths 1 and 2 are the same and opposite.

III, reflecting the laser by a reflecting mirror to enable the laser to be incident on the second retro-reflector along the propagation path 3. The propagation path 3 is axisymmetric to the propagation path 2, the axis is perpendicular to the mirror surface of the reflector to which the laser is incident, and the intersection point of the axis and the reflector is the incident point of the laser on the reflector.

IV, the second retro-reflector retro-reflects the laser to enable the laser to be incident to the reflector along the propagation path 4. The propagation paths 3 and 4 are the same and opposite in direction.

And V, reflecting the laser by a reflecting mirror to enable the laser to be incident on the first retro-reflector along the propagation route 1. After that, the laser repeats the above: the propagation process in II-V forms a resonance.

It should be noted that, in step iv, before the laser is incident on the mirror along the propagation path 4, the laser passes through the gain medium, and excites the gain medium to perform stimulated radiation, so as to generate laser with the same frequency, direction, phase and polarization state as the laser, thereby avoiding the problem of continuous attenuation of laser intensity caused by the laser being reflected by the second retro-reflector.

In the embodiment of the application, the first communication device is used for sending data, the second communication device is used for receiving data, and the central equipment is used for forwarding data.

The process of the first communication device sending data may be specifically implemented as: after the first communication device determines the data to be transmitted, the data is input into a first modulator, the first modulator modulates the data onto laser, and a first retroreflection cavity mirror retroreflects the laser (including the modulated laser) to the central equipment through retroreflection.

The process of forwarding data by the central device may specifically be implemented as follows: the mirror in the center device receives the laser light reflected from the first retrodirective mirror, and then reflects the laser light to the second retrodirective mirror of the second communication device.

The process of receiving data by the second communication device may be specifically implemented as: after the second retro-reflector in the second communication device receives the laser reflected by the reflector, a part of the laser is retro-reflected to the reflector to perform resonance, and the other part of the light is transmitted to the first demodulator. And the first demodulator demodulates the part of the transmitted laser to obtain data carried by the laser.

As follows, in the process of transmitting data to the communication device, the process of modulating laser by the modulator includes the following three scenarios: scene I, modulating the pumping power of a pumping source; scene II, modulating laser parameters; scene III, modulating the back reflection effect of the back reflection cavity mirror. The following respectively describes the scene i, the scene ii, and the scene iii:

scene I, modulating the pumping power of the pump source

The pump source is used for providing an energy source for the stimulated radiation of the gain medium. The intensity of the laser light output by the gain medium is related to the pump power of the pump source. Generally, the higher the pump power of the pump source, the higher the intensity of the laser light output by the gain medium.

Based on this, in the case of carrying data by modulating the intensity of the laser light, the modulator can adjust the intensity of the laser light output by the gain medium by adjusting the pump power of the pump source. Thereby achieving the purpose of modulating data onto the laser.

It should be noted that in this scenario, different intensities of laser light may represent different data. For example, the data signal of the laser indicator with the laser intensity in the first interval is 0, and the data signal of the laser indicator with the laser intensity in the second interval is 1.

Illustratively, the first interval may be (0, 0.1); the second interval may be (0.8, 1). That is, when the intensity of the laser is between 0 and 0.1, the data signal of the laser characterization is 0, and when the intensity of the laser is between 0.8 and 1, the data information of the laser characterization is 1.

It should be noted that in scene i, the modulator needs to be connected to the pump source, so as to adjust the pump power of the pump source.

Scene II, modulated laser parameters

Wherein the laser parameters may include: intensity, phase, polarization, orbital angular momentum, etc.

The modulator may modulate data onto the laser by modulating one or more parameters of the laser. For a parameter modulated by a modulator, the information of the modulated parameter may characterize different data signals.

In the following, the modulated laser parameters are taken as the intensity of the laser light as an example:

for example, a modulator modulates data onto a laser by modulating the intensity of light.

For example, when the data to be modulated is 0, the modulator controls the intensity of the output laser to be less than or equal to a preset value. When the data needing modulation is 1, the modulator controls the intensity of the output laser to be greater than a preset value.

Thus, when the demodulator receives the laser light, the data modulated on the laser light can be determined from the intensity of the laser light.

In the same way, the modulator may also modulate data onto the laser by modulating other parameters of the laser.

In scenario ii, the above-described two modulation schemes, namely, scheme 1 and scheme 2, may be specifically included. For a specific modulation method, reference may be made to the descriptions in the above mode 1 and mode 2, and details are not described here.

It should be noted that in the field ii, the modulator needs to be located on the propagation path of the laser light to adjust the parameters of the laser light. That is, in scene ii the modulator needs to be located between the retro-reflector and the mirror.

Scene III, modulating the retroreflective effect of a retroreflective endoscope

Wherein, the back reflection effect of back reflection chamber mirror includes: the reflectivity of the retro-reflector and the retro-reflection state of the retro-reflector.

The intensity of the laser reversely shot by the reverse cavity mirror is different under different reflectivity. Therefore, the modulator adjusts the intensity of the laser reversely shot by the reverse cavity mirror by adjusting the reflectivity of the reverse cavity mirror, and further achieves the aim of modulating data onto the laser.

The retro-reflection cavity mirror has different parameters such as polarization or orbital angular momentum of retro-reflected laser under different reflection states. Therefore, the modulator adjusts the polarization or orbital angular momentum of the laser reversely shot by the retro-reflector by adjusting the reflectivity of the retro-reflector, and further achieves the aim of modulating data onto the laser.

It should be noted that the method for modulating data onto the laser by the modulator by adjusting the polarization or orbital angular momentum of the laser is similar to the method for modulating data onto the laser by the modulator by adjusting the intensity of the laser, and is not described herein again.

It should be noted that in scene iii, the modulator is connected to the retro-reflector to adjust the retro-reflection effect of the retro-reflector.

In one possible design, fig. 6 shows the system architecture of the communication system when the gain medium and pump source are located in the central facility. In addition to this, the gain medium and the pump source may also be located in the first communication means, as shown in fig. 8 a. Alternatively, as shown in fig. 8b, the gain medium includes a first gain medium and a third gain medium, the first gain medium being located in the first communication device; the third gain medium is located in the central device.

When the gain medium and the pump source are positioned in the central equipment, the central equipment provides energy for the pump source, the communication device does not need to provide energy for laser generation, and low-power-consumption communication of the communication device can be realized.

When the gain medium and the pumping source are positioned in the first communication device, the first communication device can better control the power of the laser, and different communication devices can select the lasers with different powers to communicate, so that a better communication function is realized.

In one possible design, based on the communication system shown in fig. 6, as shown in fig. 9, the second communication device further includes a second modulator; the first communication device also includes a first demodulator.

The second modulator is used for modulating second data onto the laser to generate second modulated laser; the second modulated laser carries second data.

And the second retro-reflection cavity mirror is also used for retro-reflecting the second modulated laser to the reflecting mirror.

The first retro-reflection cavity mirror is also used for retro-reflecting and transmitting the second modulated laser from the reflecting mirror; the first demodulator is used for demodulating the second modulated laser and acquiring second data carried by the second modulated laser.

Based on the above technical solution, the first communication device is added with the first demodulator, so that the first communication device has a function of receiving data. The second communication device is added with a second modulator, so that the second communication device has a function of transmitting data. Based on this, bidirectional communication can also be realized between the first communication device and the second communication device.

It should be noted that, the second communication device sends data, and the process of receiving data by the second communication device may refer to the foregoing description, which is not described herein again.

In one possible design, as shown in fig. 10 in conjunction with fig. 9, a gain medium (denoted as a second gain medium) and a pump source (denoted as a second pump source) may also be provided in the second communication device. In this way, when the second communication device transmits data, the laser beams with different powers can be selected for communication, so that a better communication function is realized.

In one possible design, in conjunction with fig. 9, as shown in fig. 11, the center device may further include: a third demodulator. Accordingly, the mirrors in the central apparatus are capable of transmitting laser light in addition to reflecting laser light.

The third demodulator is positioned on the side of the reflector transmitting the laser light. The laser light transmitted by the reflecting mirror comprises third modulated laser light.

The third modulated laser carries third data. The third demodulator is used for demodulating the third modulated laser and acquiring third data carried by the third modulated laser; the third modulated laser is reflector transmission laser;

based on this, the center device demodulates the modulated laser light through the third demodulator, so that the center device has a function of receiving data. Thereby realizing communication between the center device and the communication apparatus.

In addition, the center device may listen to a communication procedure between the first communication apparatus and the second communication apparatus according to the function of receiving data, thereby adjusting the communication conditions of the first communication apparatus and the second communication apparatus.

For example, when the pump source and the gain medium are provided in the center apparatus, the center apparatus can determine the number of communication devices currently communicating by listening to the communication conditions between all the communication devices. The central apparatus can adjust the pump power of the pump source according to the number of communication devices currently communicating. So as to keep the communication between the communication devices with laser light with relatively stable power.

Specifically, in the case where the pump source and the gain medium are provided in the center apparatus, since the power of the pump source is constant, if the number of communication device pairs (i.e., two or more communication devices communicating with each other) in the communication state in the system increases, the energy allocated to each communication device pair by the center apparatus decreases. The power of the laser light transmitted between the pair of communication devices is reduced, and data transmission between the communication devices needs to be performed at a lower rate to ensure the accuracy of data transmission.

In this case, if the central device has a function of receiving data, the central device may monitor the number of communication device pairs in a communication state in the system, and further adjust the pump power of the pump source, so as to ensure that data can be transmitted between the communication devices by laser with stable power.

In one possible design, a third retro-reflector may also be included in the central device, as shown in fig. 11. The third retro-reflector is positioned on one side of the reflector for reflecting the laser.

The third retro-reflector is used for receiving the laser from the first retro-reflector or the second retro-reflector and transmitting and/or retro-reflecting the laser from the first retro-reflector or the second retro-reflector.

The third retro-reflector has a retro-reflection function and a transmission function. At this time, the mirror in the center device can be adjusted to a fully transmissive state. That is, at this time, the mirror in the center device may not reflect the laser light, but transmit only the laser light.

Therefore, between the central equipment and the communication device, the resonant cavity is formed by the central equipment and the two retro-reflector mirrors of the communication device, and the communication between the single communication device and the central equipment can be realized.

For example, if the first communication device needs to transmit data to the center device, the first communication device retroreflects the modulated laser light to the third retroreflection cavity mirror of the center device through the first retroreflection cavity mirror. The third retro-reflector reflects part of the laser so as to form resonance between the first retro-reflector and the third retro-reflector; the third retro-reflector transmits part of laser, and a third demodulator in the central equipment demodulates the transmitted laser to determine data carried by the laser.

It is noted that the third retro-reflector mirror may in particular be located at a side of the gain medium facing the first retro-reflector mirror and/or the second retro-reflector mirror. Or between the gain medium and the mirror. This is not limited in this application.

In one possible design, in conjunction with fig. 11, as shown in fig. 12a, 12b or 12c, the center device may further include a third modulator; the third modulator is used for modulating data to the laser and generating modulated laser.

In this way, the center device can send information to the communication device, thereby achieving control and adjustment of the communication device.

As shown in fig. 12a, the third modulator may be located on the side of the gain medium facing the first and/or second retro-cavity mirror.

In this way, the third modulator can modulate data onto the laser light in the manner described in the above-mentioned scenario ii.

Alternatively, the third modulator may be located between the gain medium and the mirror, as shown in fig. 12 b.

In this way, the third modulator can modulate data onto the laser light in the manner described in the above-mentioned scenario iii.

Still alternatively, as shown in fig. 12c, the third modulator is connected to the pump source in the central apparatus.

Thus, the third modulator can modulate data onto the laser in the manner described in the above-mentioned scenario i.

In one possible design, when there are a plurality of communication devices in the system, each communication device may communicate with a communication device located within the coverage area of the communication device (i.e., located within the range to which the laser light reflected by the communication device can be reflected by the mirror).

For example, the second communication device is within the coverage of the first communication device, the first communication device may transmit data to the second communication device. Likewise, the first communication device is located within the coverage area of the second communication device according to the principle of reversible optical paths.

If there are multiple communication devices within the coverage of each other, these communication devices can all communicate with each other. These communication devices may be unicast, multicast or broadcast to each other. I.e. one communication device may transmit data to one or more communication devices that are within coverage of each other.

The central apparatus may divide the communication devices mutually located within the coverage of each other into a group of communication devices. It is assumed that the communication devices connected to the center apparatus are divided into two communication device groups, a first communication device group and a second communication device group. Wherein the communication device of the first communication device group is not within the coverage of the communication device of the second communication device group, nor is the communication device of the second communication device group within the coverage of the communication device of the first communication device group.

Thus, the communication devices in both communication device groups will not be aware of each other's communication device between the other communication device group. Since the communication devices in both communication device groups are both energized by the pump source in the central facility when communicating, these communication devices will share the pump energy of the pump source in the central facility when communicating. Therefore, the larger the number of communication devices in the communication state among the communication devices, the lower the energy allocated to each communication device group by the center apparatus. The power of the laser light transmitted between the communication devices of the group is reduced, and data transmission between the communication devices needs to be performed at a lower rate to ensure the accuracy of the data transmission.

For example, the first communication device group includes m communication devices, which are respectively: { U1, U2, …, Um }. The second communication device group comprises n communication devices, which are respectively: { V1, V2, …, Vn }. m and n are both positive integers.

While the U1 and U2 within the first group of communication devices are communicating, the V1 and V2 within the second group also need to communicate. If V1 and V2 communicate directly, the central equipment needs to allocate a certain amount of energy for V1 and V2 communication. At this time, the intensity of the laser light transmitted between U1 and U2 will change, that is, V1 and V2 will interfere with the communication between U1 and U2.

In this case, the center apparatus can avoid the power reduction of the laser in both the following manner a and manner b.

Mode a, adjusting the pumping power of the pumping source.

In this manner, the central device may allow V1 and V2 to communicate. The central equipment adjusts the pumping power of the pumping source according to the number of the communication devices which are currently in communication so as to ensure that the data can be transmitted between the communication devices by laser with stable power.

And b, allocating corresponding communication time periods to each pair of communication devices.

In this manner, the center device allocates the respective communication periods to V1 and V2, and indicates the communication periods thereof to V1 and V2 by the second indication information. The V1 and V2, after receiving the second indication information, communicate within the communication period according to the communication period indicated by the second indication information. In this way, each pair of communication apparatuses communicate in the communication period allocated thereto, and interference with each other can be avoided.

Specifically, in the method b, when the communication device needs to perform communication, first, the first instruction information is transmitted to the center device; the first indication information is used for indicating that the communication device requests to perform communication.

After receiving the first indication information from the communication device, the center device communicates with the communication device and negotiates a communication period of the communication device. After the negotiation is successful, the central equipment generates second indication information according to the negotiated communication time interval; the second indication information is used for indicating the communication device to communicate in the preset communication time period.

The center device transmits the second indication information to the communication apparatus.

After receiving the second indication information, the communication device communicates within the communication period indicated by the second indication information.

In a possible implementation manner of the manner b, the center device may further send third indication information to the communication apparatus. The third indication information is used for synchronizing the communication apparatus. E.g. synchronized time-frequency resources. Or synchronizing system configuration information, etc.

And the communication device receives the third indication information from the central equipment and carries out synchronization according to the third indication information.

It should be noted that the center device may transmit the third indication information periodically or may transmit the third indication information non-periodically.

When the center device periodically transmits the third indication information, the communication device may also periodically receive the third indication information and perform synchronization.

When the center device transmits the third indication information aperiodically, the communication apparatus may receive the third indication information only in a communication period of its communication. When the center apparatus transmits the third indication information aperiodically, the center apparatus may determine a time interval for transmitting the third indication information according to the number of communication devices accessing the center apparatus, the number of communication devices in a communication state, and the like.

Illustratively, the central device periodically sends third indication information, and the third indication information is used for time synchronization. As shown in fig. 13, the center apparatus divides time into a plurality of periods and indicates a time length of each period by the third indication information. The third indication information identifies a start time and an end time of each period in the form of a beacon. Each pair of communication devices requiring communication may communicate during different communication periods of different cycles. For example, as shown in fig. 13, U1 communicates with U2 in the first communication period of the first cycle. V1 communicates with V2 during the second communication period of the first cycle. U3 communicates with U4 during the first communication period of the second cycle.

The center device periodically transmits the third indication information to enable the communication device to determine the time length of each period. When the communication device needs to communicate, the center device negotiates with the communication device and allocates one or more communication periods within one or more periods to the communication device.

In one possible design, for the communication devices in the same group, the communication device may monitor the communication conditions of the other communication devices in the group and adjust the data transmission rate of the communication device according to the communication conditions of the other communication devices in the group.

For example, during the course of the U1 being in communication with the U2, the U3 needs to send data to the U4. The U3 first listens to the communication situation of the communication devices in the same group, and finds that U1 is communicating with U2, at this time, U3 negotiates with U1 and U2 to determine the time period for each communication, or U1 communicates with U2 and U3 communicates with U4 simultaneously, and the two respectively select lower transmission rate to transmit data, so as to reduce the interference between the communications.

It should be noted that the reception of data by the communication device and the central device during the listening process also consumes energy in the system, thereby reducing the power of the laser in the system. In this case, in order to avoid the interference, a listening margin may be set in the communication system, and when the center device and the communication apparatus receive or transmit data at the transmission rate of the first listening margin, the communication apparatus that is communicating may not be interfered with. The central facility and the communication device transmit a check-in signal prior to listening to detect an allowed listening margin in the system.

In one possible design, as shown in fig. 14 in conjunction with fig. 10, a communication device of a communication system includes: a light shutter; the communication device is at least one of a first communication device and a second communication device.

The optical shutter is positioned on one side of the target retro-reflector cavity mirror for retro-reflecting laser, is in different states and can control the intensity of the laser entering the retro-reflector cavity mirror; the retrodirective cavity mirror is a retrodirective cavity mirror in the communication device. Based on this, when the optical shutter is in the state of transmitting laser light with certain intensity, the communication device can carry out resonance to transmit data; when the optical shutter is not transmitting any laser light, the communication device will not resonate, reducing the energy consumption of communication. In addition, in the case where different intensities of laser light represent different data, the modulator may also modulate the data onto the laser light by adjusting the light transmittance of the optical shutter.

It should be noted that, in the embodiment of the present application, the function of the optical shutter may also be replaced by providing a modulator whose transmittance is adjustable. In this case, the modulator needs to be located on the laser retroreflection side of the retroreflection cavity mirror. The light transmittance of the modulator is different, and the intensity of the laser entering the retro-reflector cavity mirror can be controlled.

In one possible design, as shown in fig. 15 in conjunction with fig. 14, a communication device of a communication system includes:

a filter disc; the communication device is at least one of a first communication device and a second communication device; the filter disc is positioned on one side of the back-reflection cavity mirror for back-reflection of laser; the filter disc is used for filtering target laser; the parameters of the target laser and the laser with preset parameters are different; wherein the parameters of the laser are one or more of the following: wavelength, polarization, and orbital angular momentum; the retrodirective cavity mirror is a retrodirective cavity mirror in the communication device. Based on this, the communication device filters the target laser through the filter disc, so that the laser received by the communication device is the laser which needs to be received by the communication device, the interference of the target laser to the laser which needs to be demodulated by the communication device is reduced, and the target laser is prevented from influencing the demodulation performance of the demodulator.

In one possible design, the light transmittance of any one or more of the reflector, the first retro-reflector, the second retro-reflector and the third retro-reflector can be adjusted. Based on this, the modulator can modulate data onto the laser by adjusting the light transmittance of the retro-reflector.

It should be noted that the light transmittance of the reflector, the first retro-reflector, the second retro-reflector and the third retro-reflector can be adjusted by the modulator according to the data to be modulated.

Taking the first retro-reflector as an example, the modulator generates a corresponding electrical signal according to the data to be modulated. The modulator sends the electrical signal to the first retro-reflector. After the first retro-reflector receives the electric signal, the light transmittance of the first retro-reflector is adjusted according to the electric signal.

In one possible design, one gain medium in the embodiment of the present application includes a plurality of sub gain media. The wavelengths of the light generated after the different sub gain mediums are excited and radiated are different. The one gain medium may be one or more of a first gain medium, a second gain medium, and a third gain medium.

As shown in fig. 16, the third gain medium in the center device is exemplified to include the first sub gain medium and the second sub gain medium. As shown in fig. 16, the coverage area of the first communication device on the first sub gain medium is area 1. If the wavelength of the laser generated by the stimulated emission of the first sub-gain medium is a, the first communication device communicates with other communication devices through the laser with the wavelength a in the area 1. If the wavelength of the laser light generated by the stimulated emission of the second sub gain medium is b, the first communication device communicates with another communication device through the laser light with the wavelength b in the region 2.

Therefore, the communication ranges covered by the laser beams with different wavelengths are different, and the communication devices in the coverage ranges communicate by adopting the laser beams with the corresponding wavelengths, so that the interference among the communication devices can be avoided. In addition, the laser with a plurality of wavelengths is adopted for communication, so that wavelength division multiplexing of the laser with different wavelengths can be realized, and the system capacity of a communication system is improved.

In a possible implementation manner, a process of modulating data onto laser by the first modulator, the second modulator, and the third modulator is described in detail with reference to the above-described scene i, scene ii, and scene iii.

Case 1 for a first modulator

Combining the scene I, the first modulator and the first pumping source to be connected; the first modulator is used for adjusting the pumping power of the first pumping source according to the first data; the first gain medium outputs laser light with corresponding power according to the pumping power of the first pumping source, and the laser light with corresponding power carries first data.

In combination with the above scenario ii, the first modulator is located in the first communication device and between the first retro-reflector and the mirror. The first modulator modulates data onto the laser light before the laser light is transmitted to the first retro-reflector cavity mirror. The first retro-reflector cavity mirror retro-reflects the modulated laser.

Combining the scene III and the first modulator to be connected with the first retro-reflector; the first modulator is used for adjusting the reflecting state of the first reflecting cavity mirror according to the first data; the first retrodirective cavity mirror retrodirective emits laser with corresponding parameters according to the retrodirective state, and the laser with the corresponding parameters bears first data.

Case 2 for the second modulator

Combining the scene I and the second modulator to be connected with a second pumping source; the second modulator is used for adjusting the pumping power of the second pumping source according to the second data; the second gain medium outputs laser light with corresponding power according to the pumping power of the second pumping source, and the laser light with corresponding power carries second data. Based on this, the second modulator can modulate the data by adjusting the pump power of the second pump source.

In combination with the above scenario ii, the second modulator is located in the second communication device, between the second retro-reflector and the mirror. The second modulator modulates data onto the laser light before the laser light is transmitted to the second retro-reflector cavity mirror. The second retro-reflector cavity mirror retro-reflects the modulated laser.

Combining the scene III, and connecting the second modulator with a second retro-reflector; the second modulator is used for adjusting the reflecting state of the second reflecting cavity mirror according to the second data; the second retrodirective cavity mirror retrodirective irradiates the laser with the corresponding parameter according to the retrodirective state, and the laser with the corresponding parameter bears second data.

Case 3, third modulator

For the third modulator, the third modulator is connected with the third pump source in combination with the scene i, and the third modulator is configured to adjust the pump power of the pump source according to fourth data; the third gain medium outputs laser with corresponding power according to the pumping power of the pumping source, and the laser with corresponding power carries fourth data.

And the third modulator is positioned in the central equipment in combination with the scene II, and the reflector reflects one side of the laser. The third modulator modulates data onto the laser light before the laser light is transmitted to the mirror. The mirror reflects the modulated laser light.

Combining the scene III and the third modulator to be connected with the reflector; the third modulator is used for adjusting the reflection state of the reflector according to the fourth data; the reflector reflects the laser with the corresponding parameters according to the reflection state, and the laser with the corresponding parameters bears fourth data.

In a possible implementation manner, the reflecting mirror described in the embodiments of the present application may be a flat mirror, a curved mirror, or a combination of multiple mirrors, such as a folding mirror. In case the mirror is a convex mirror, a larger coverage is usually obtained.

Based on the above communication system, as shown in fig. 17, an embodiment of the present application provides a communication apparatus, including: a first modulator and a first retro-reflector; the first modulator is used for modulating first data onto laser to generate first modulated laser, and the first modulated laser carries the first data; and the first retro-reflection cavity mirror is used for retro-reflecting the first modulated laser to the central equipment.

Based on the technical scheme, in the laser communication process, the communication device adopts the first retro-reflection cavity mirror to retro-reflect laser. The laser reflected by the first retro-reflector is retro-reflected to the reflector and is reflected to the second retro-reflector of other communication devices by the reflector. Therefore, the first retro-reflection cavity mirror and the second retro-reflection cavity mirror are reflected by the reflecting mirror to form resonance, and the communication device and other communication devices can communicate through laser reflected by the reflecting mirror, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

In one possible design, as shown in fig. 17, the communication device further includes: a first demodulator; the first demodulator is used for demodulating the second modulated laser and acquiring second data carried by the second modulated laser; the second modulated laser is laser which is reversely reflected and transmitted by the first retro-reflector cavity mirror and comes from the central equipment; the second modulated laser carries second data.

In one possible design, as shown in fig. 17, the first modulator is connected to a first retro-reflector; the first modulator is used for adjusting the reflecting state of the first reflecting cavity mirror according to the first data; the first retrodirective cavity mirror retrodirective emits laser with corresponding parameters according to the retrodirective state, and the laser with the corresponding parameters bears first data.

In one possible design, as shown in fig. 17, the communication device further includes: a first gain medium and a first pump source; the first gain medium generates laser under the action of a first pump source; the first pumping source is connected with the first gain medium; the first pump source is used to provide energy to the first gain medium. The first modulator is connected with the first pumping source; the first modulator is used for adjusting the pumping power of the first pumping source according to the first data; the first gain medium outputs laser light with corresponding power according to the pumping power of the first pumping source, and the laser light with corresponding power carries first data.

Based on the above communication system, as shown in fig. 18, an embodiment of the present application further provides a communication apparatus, including: a second demodulator and a second retro-reflector; a second retroreflection cavity mirror for retroreflecting and transmitting the first modulated laser light from the center device; the first modulated laser carries first data; and the second demodulator is used for demodulating the first modulated laser transmitted by the second retro-reflector to acquire first data carried by the first modulated laser.

Based on the technical scheme, in the laser communication process, the communication device adopts the second retro-reflection cavity mirror to retro-reflect and transmit laser. For the retrodirective laser, the retrodirective laser can be retrodirective reflected on the reflector and reflected by the reflector to a retrodirective cavity mirror of other communication devices. Therefore, the first retro-reflection cavity mirror and the second retro-reflection cavity mirror are reflected by the reflecting mirror to form resonance, and the communication device and other communication devices can communicate through laser reflected by the reflecting mirror, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

In addition, the second retro-reflector transmits part of the laser light, so that the second demodulator can acquire the modulated laser light. The second modulator may acquire data carried by the modulated laser by demodulating the modulated laser.

In one possible design, as shown in fig. 18, the communication device further includes: a second modulator; the second modulator is used for modulating second data onto the laser to generate second modulated laser; the second modulated laser carries second data; and the second retro-reflection cavity mirror is also used for retro-reflecting the second modulated laser to the central equipment.

In one possible design, as shown in FIG. 18, the second modulator is connected to a second retro-reflector; the second modulator is used for adjusting the reflecting state of the second reflecting cavity mirror according to the second data; the second retrodirective cavity mirror retrodirective irradiates the laser with the corresponding parameter according to the retrodirective state, and the laser with the corresponding parameter bears second data. Based on this, the second modulator may modulate the data by adjusting the retro-reflective state of the second retro-reflector cavity mirror.

In one possible design, as shown in fig. 18, the communication device further includes: a second gain medium and a second pump source; the second gain medium generates laser under the action of a second pump source; the second pumping source is connected with the second gain medium; the second pump source is used to energize the second gain medium. The second modulator is connected with a second pumping source; the second modulator is used for adjusting the pumping power of the second pumping source according to the second data; the second gain medium outputs laser light with corresponding power according to the pumping power of the second pumping source, and the laser light with corresponding power carries second data.

In one possible design, as shown in fig. 17 or fig. 18, the communication device further includes: a light shutter; the optical shutter is positioned on one side of the retro-reflector cavity mirror for retro-reflecting the laser, is in different states and can control the intensity of the laser entering the retro-reflector cavity mirror; the retro-reflector is a first retro-reflector or a second retro-reflector.

In one possible design, as shown in fig. 17 or fig. 18, the communication device further includes: a filter disc; the filter disc is positioned on one side of the back-reflection cavity mirror for back-reflection of laser; the filter disc is used for filtering target laser; the parameters of the target laser and the laser with preset parameters are different; wherein the parameters of the laser include one or more of: wavelength, polarization, and orbital angular momentum; the retro-reflector is a first retro-reflector or a second retro-reflector.

In one possible design, the communication device is further configured to send first indication information to the center device; the first indication information is used for indicating that the communication device requests to perform communication.

In one possible design, the communication device is further configured to receive second indication information from the central device; the second indication information is used for indicating the communication device to communicate in a preset communication time period; the communication device communicates with other communication devices within a preset communication period.

In one possible design, the communication device is further configured to adjust a rate at which the communication device transmits data according to the number of other communication devices.

In one possible design, the communication device is further configured to receive third indication information from the central apparatus; the third indication information is used for synchronizing the communication device; and the communication device carries out synchronization according to the third indication information.

In one possible design, the light transmittance of the retro-reflector cavity mirror can be adjusted, and the retro-reflector cavity mirror is a first retro-reflector cavity mirror or a second retro-reflector cavity mirror.

In one possible design, at least one of the first gain medium and the second gain medium includes a plurality of sub gain media; the wavelengths of the laser generated after the different sub gain mediums are excited and radiated are different.

Based on the above communication system, as shown in fig. 19, an embodiment of the present application provides a center device, including: a mirror, a third gain medium and a third pump source; the third gain medium generates laser under the action of a third pump source; the third pumping source is connected with the third gain medium; the third pump source is used for providing energy for the third gain medium; and the reflector is used for reflecting the laser modulated by the first communication device to the second communication device, and the modulated laser carries the first data sent by the first communication device.

Based on the technical scheme, in the laser communication process, the central equipment reflects the laser modulated by the first communication device to the second communication device. Thus, the first retro-reflector of the first communication device and the second retro-reflector of the second communication device can be reflected by the reflector to form resonance, and the first communication device and the second communication device can communicate through laser reflected by the reflector, so that non-line-of-sight communication is realized. Because the reflection effect of the reflector is usually far better than the reflection and scattering effects of the environment, the communication device, the central equipment and the communication system provided by the application can carry out non-line-of-sight transmission by using larger laser power, and the transmission rate of laser communication is greatly improved.

In one possible design, as shown in FIG. 19, the mirror is capable of transmitting laser light; the center device further includes: a third demodulator; the third demodulator is positioned on one side of the reflector for transmitting the laser; the third demodulator is used for demodulating the third modulated laser and acquiring third data carried by the third modulated laser; the third modulated laser is reflector transmission laser; the third modulated laser carries third data.

In one possible design, as shown in fig. 19, the center device further includes: a third retro-reflector; the third retro-reflector is positioned on one side of the reflector for reflecting the laser; the third retro-reflector is used for transmitting and retro-reflecting laser.

In one possible design, as shown in fig. 19, the third retro-reflector cavity mirror is located on a side of the third gain medium facing the communication means, which is at least one of the first communication means and the second communication means.

In one possible design, the third retro-reflector mirror is located between the gain medium and the mirror, as shown in fig. 19.

In one possible design, as shown in fig. 19, the center device further includes: a third modulator; the third modulator is used for modulating the fourth data to the laser to generate fourth modulated laser; the center device is also used for sending the fourth modulated laser to the communication device.

In one possible design, the third modulator is located on the side of the third gain medium facing the communication device, as shown in fig. 19.

In one possible design, the third modulator is located between the third gain medium and the mirror, as shown in fig. 19.

In one possible design, as shown in fig. 19, a third modulator is connected to the third pump source, the third modulator is used to adjust the pump power of the pump source according to the fourth data; the third gain medium outputs laser with corresponding power according to the pumping power of the pumping source, and the laser with corresponding power carries fourth data.

In one possible design, the central device is further configured to receive first indication information from the communication apparatus; the first indication information is used for indicating that the communication device requests to perform communication.

In one possible embodiment, the central device is further configured to send second indication information to the communication device; the second indication information is used for indicating the communication device to communicate in the preset communication time period.

In one possible design, the center device is further configured to send third indication information to the communication apparatus; the third indication information is used for synchronizing the communication apparatus.

In one possible design, the central device is further configured to adjust the pump power of the third pump source according to the number of communication devices accessing the central device.

In one possible design, the light transmittance of any one or more of the mirror and the third retro-reflector can be adjusted.

In one possible design, the third gain medium includes a plurality of sub-gain media; the wavelengths of the laser generated after the different sub gain mediums are excited and radiated are different.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions described in accordance with the embodiments of the present application are all or partially generated upon loading and execution of computer program instructions on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). Computer-readable storage media can be any available media that can be accessed by a computer or can comprise one or more data storage devices, such as servers, data centers, and the like, that can be integrated with the media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

While the present application has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.