阅读说明：本技术 一种变频温控光纤激光器系统 (Frequency conversion temperature control fiber laser system ) 是由 高放 沈国新 张先明 丁建武 刘进辉 于 2021-08-29 设计创作，主要内容包括：一种变频温控光纤激光器系统,包括温度控制平台和控制系统,温度控制平台上设置若干半导体激光器、N+1光纤合束器和光纤增益腔,光纤增益腔的输出端连接光纤输出光缆；控制系统包括控制电路与控制系统软件,控制系统软件包括半导体激光器供电控制系统、温度控制系统与温度监控系统,半导体激光器供电控制系统与半导体激光器相连接,温度监控系统与温度控制系统相连接,温度控制系统的输出端与相变式变频压缩热量交换系统的控制端相连接,相变式变频压缩热量交换系统的冷媒流道与温度控制平台相连接。本发明克服了现有光纤激光器非水冷技术的不足,可实现一台激光器输出多种不同的光束形状,通过单台激光器就可以分别实现光纤激光器、复合激光系统与半导体激光器的功能。(A frequency conversion temperature control optical fiber laser system comprises a temperature control platform and a control system, wherein the temperature control platform is provided with a plurality of semiconductor lasers, an N +1 optical fiber beam combiner and an optical fiber gain cavity, and the output end of the optical fiber gain cavity is connected with an optical fiber output optical cable; the control system comprises a control circuit and control system software, the control system software comprises a semiconductor laser power supply control system, a temperature control system and a temperature monitoring system, the semiconductor laser power supply control system is connected with the semiconductor laser, the temperature monitoring system is connected with the temperature control system, the output end of the temperature control system is connected with the control end of the phase-change type variable-frequency compression heat exchange system, and a refrigerant flow channel of the phase-change type variable-frequency compression heat exchange system is connected with the temperature control platform. The invention overcomes the defects of the non-water cooling technology of the existing fiber laser, can realize that one laser outputs various different beam shapes, and can respectively realize the functions of the fiber laser, a composite laser system and a semiconductor laser through a single laser.)

1. A frequency conversion temperature control fiber laser system is characterized in that: the temperature control system comprises a temperature control platform (1) and a control system (2), wherein a plurality of semiconductor lasers (3), an N +1 optical fiber beam combiner (4) and an optical fiber gain cavity (5) are arranged on the temperature control platform (1), the laser output ends of the semiconductor lasers (3) are matched with the input end of the N +1 optical fiber beam combiner (4), the output end of the N +1 optical fiber beam combiner (4) is connected with the input end of the optical fiber gain cavity (5), and the output end of the optical fiber gain cavity (5) is connected with an optical fiber output optical cable (6);

control system includes semiconductor laser power supply control system (21), temperature control system (22) and temperature monitoring system (23), semiconductor laser power supply control system (21) and semiconductor laser (3) electrode connection, temperature monitoring system (23) are used for carrying out real-time temperature monitoring, the signal output part of temperature monitoring system (23) is connected with the signal input part of temperature control system (22), the output of temperature control system (22) is connected with the control end of heat exchange system (7).

2. The variable frequency, temperature controlled fiber laser system of claim 1, wherein the control system enables the laser to achieve three modes of output, mode 1 being a high energy density, small spot laser beam, mode 2 being a low energy density, large spot laser beam, and mode 3 being a central, high energy density, peripheral, low energy density, composite spot beam.

3. The variable frequency, temperature controlled fiber laser system of claim 1, wherein: the optical fiber gain cavity (5) comprises an ytterbium-doped gain optical fiber (51), a first grating (52) and a second grating (53) which are positioned at two ends of the ytterbium-doped gain optical fiber (51), the output end of the N +1 optical fiber beam combiner (4) is connected with the first grating (52), and the output end of the second grating (53) is connected with an optical fiber output optical cable (6).

4. The variable frequency, temperature controlled fiber laser system of claim 1, wherein: the optical fiber output optical cable (6) is a water-cooling-free QBH output optical cable.

5. The variable frequency, temperature controlled fiber laser system of claim 1, wherein: the monitoring end of the temperature monitoring system (23) is positioned on the temperature control platform (1), the control system (2) comprises a control circuit and control system software, the heat exchange system is a phase-change type variable-frequency compression system, and a refrigerant flow channel of the phase-change type variable-frequency compression system (7) is connected with the temperature control platform (1).

6. The variable frequency temperature controlled fiber laser system of claim 1, the phase change variable frequency compression system (7) comprising a variable frequency compressor, a condenser, an evaporator, an expansion valve, a fan.

7. The variable frequency, temperature controlled fiber laser system of claim 1, wherein the plurality of semiconductor lasers are semiconductor lasers having the same output wavelength.

8. The variable frequency temperature controlled fiber laser system of claim 6, the phase change variable frequency compression system (7) further comprising an electromagnetic four-way reversing valve.

Technical Field

The invention relates to the technical field of fiber lasers, in particular to a frequency-conversion temperature-control multimode selective fiber laser system.

Background

A976 nm pumped optical fiber laser in a high-power laser has high photoelectric conversion efficiency and high energy density, but has the problem of narrow absorption peak, and the conventional water-cooling or air-cooling temperature control system is difficult to ensure the accuracy of the temperature of a pumping light source, so that the pumping efficiency is reduced.

In the optical fiber laser, the output beam spot mode output by the traditional laser is generally single; the traditional industrial laser depends on huge water-cooling equipment outside the laser, and the adjustable interval of water-cooling is small, the reaction is slow, and the movement is inconvenient, so that the factors greatly restrict various applications and applicable scenes of the laser; meanwhile, the existing air-cooled laser has low heat dissipation efficiency, small temperature control range and low output power; at present, there are also fiber lasers with multiple spot output modes, which basically rely on increasing the semiconductor laser that can output a fixed wavelength (non-absorption range), or using the way of changing the current to change the output wavelength of the semiconductor laser, and use the above way to generate the pumping light that is not absorbed by the gain cavity system of the fiber laser.

The existing fiber laser with multiple output modes is basically realized by adding a semiconductor laser capable of generating fixed wavelength (non-absorption range), and is partially realized by adjusting current; but has the disadvantages that: 1. the principle of current regulation is that the absorption rate of a gain cavity of a semiconductor laser is changed by utilizing the characteristic that the semiconductor laser outputs different wavelengths at different currents, so that a composite light spot form is generated; in the method, the electro-optical efficiency of the laser is low at low current, and the stability of the laser is poor at high current; 2. by adding a semiconductor laser with fixed wavelength (non-absorption range), the cost is high due to the additional semiconductor laser, and a special beam combiner needs to be matched, so that the limitation of an optical device is large; 3. the traditional optical fiber laser basically needs an external water cooling system and is low in air cooling output power.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a variable-frequency temperature-control fiber laser system, which overcomes the defects of the prior art, has reasonable design, can realize that one non-water-cooled laser outputs various different beam shapes, and can respectively realize the functions of a fiber laser, a composite laser system and a semiconductor laser through a single laser.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a frequency conversion temperature control optical fiber laser system comprises a temperature control platform and a control system, wherein a plurality of semiconductor lasers, an N +1 optical fiber beam combiner and an optical fiber gain cavity are arranged on the temperature control platform, the laser output ends of the semiconductor lasers are matched with the input end of the N +1 optical fiber beam combiner, the output end of the N +1 optical fiber beam combiner is connected with the input end of the optical fiber gain cavity, and the output end of the optical fiber gain cavity is connected with an optical fiber output optical cable; the semiconductor lasers adopt semiconductor lasers with the same output wavelength.

The control system comprises a control circuit and control system software, the control system software comprises a semiconductor laser power supply control system, a temperature control system and a temperature monitoring system, the semiconductor laser power supply control system is connected with the semiconductor laser, a monitoring end of the temperature monitoring system is positioned on a temperature control platform and used for monitoring the temperature of the temperature control platform in real time, a signal output end of the temperature monitoring system is connected with a signal input end of the temperature control system, an output end of the temperature control system is connected with a control end of the phase-change type frequency conversion compression heat exchange system, and a refrigerant flow channel of the phase-change type frequency conversion compression heat exchange system is connected with the temperature control platform.

The phase-change type variable-frequency compression heat exchange system 7 consists of a variable-frequency compressor, a condenser, an evaporator, an expansion valve and a variable-frequency fan, is used for providing temperature control with large temperature difference for the semiconductor laser, and can also comprise an electromagnetic four-way reversing valve, a refrigerant liquid storage tank and the like. The adoption of the electromagnetic four-way reversing valve can enable the laser to have the capability of starting and stable use in an extremely cold environment.

Preferably, the temperature control platform may further comprise a PTC heating tube for heating when the preset temperature is lower so that the pump laser rapidly reaches a predetermined temperature.

Preferably, the optical fiber gain cavity comprises a ytterbium-doped gain optical fiber, and a first grating and a second grating which are positioned at two ends of the ytterbium-doped gain optical fiber, the output end of the N +1 optical fiber combiner is connected with the first grating, and the output end of the second grating is connected with the optical fiber output optical cable.

Preferably, the optical fiber output cable is a non-water-cooled QBH output cable.

The invention provides a variable-frequency cooling multimode selective fiber laser system. The method has the following beneficial effects: the power of the phase-change type variable-frequency compression heat exchange system 7 is controlled through the temperature control system 22, so that the temperature of the temperature control platform can be subjected to variable-frequency adjustment in real time, and the temperature control is more accurate; and controlling the output wavelength of the semiconductor laser by changing the temperature; the semiconductor can be ensured to work under a stable wavelength condition all the time, and the output with the maximum efficiency is realized; and can realize that a laser outputs multiple different beam modes, can realize the function of high density fiber laser, compound laser system and semiconductor laser respectively through single laser.

Drawings

In order to more clearly illustrate the present invention or the prior art solutions, the drawings that are needed in the description of the prior art will be briefly described below.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic block diagram of the control system of the present invention;

the reference numbers in the figures illustrate:

1. a temperature control platform; 2. a control system; 3. a semiconductor laser; 4. an N +1 optical fiber combiner; 5. a fiber gain cavity; 6. an optical fiber output cable; 7. a phase-change variable-frequency compression heat exchange system; 21. a semiconductor laser power supply control system; 22. a temperature control system; 23. a temperature monitoring system; 51. an ytterbium-doped gain fiber; 52. a first grating; 53. a second grating.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings.

As shown in fig. 1-2, a frequency conversion temperature control fiber laser system includes a temperature control platform 1 and a control system 2, wherein the temperature control platform 1 is provided with a plurality of semiconductor lasers 3, N +1 optical fiber beam combiners 4 and an optical fiber gain cavity 5, the laser output ends of the semiconductor lasers 3 are all matched with the input ends of the N +1 optical fiber beam combiners 4, the output end of the N +1 optical fiber beam combiner 4 is connected with the input end of the optical fiber gain cavity 5, and the output end of the optical fiber gain cavity 5 is connected with an optical fiber output cable 6; the semiconductor lasers adopt semiconductor lasers with the same output wavelength.

The control system 2 comprises a control circuit and control system software, the control system software comprises a semiconductor laser power supply control system 21, a temperature control system 22 and a temperature monitoring system 23, the semiconductor laser power supply control system 21 is connected with the semiconductor laser 3 and is used for performing power supply regulation control on the semiconductor laser 3 and controlling the output power of a semiconductor; the monitoring end of the temperature monitoring system 23 is positioned on the temperature control platform 1 and is used for monitoring the temperature of the temperature control platform 1 in real time, the signal output end of the temperature monitoring system 23 is connected with the signal input end of the temperature control system 22, the output end of the temperature control system 22 is connected with the control end of the phase-change type variable-frequency compression heat exchange system 7, and the refrigerant flow channel of the phase-change type variable-frequency compression heat exchange system 7 is connected with the temperature control platform 1; the temperature control system 22 is used for sending different working instructions to the phase-change type variable-frequency compression heat exchange system 7 so as to control the temperature of the temperature control platform 1 at different temperatures; and the real-time temperature of the temperature control platform 1 is adjusted by combining the temperature monitoring system 23 to the phase-change type variable-frequency compression heat exchange system 7, so that the temperature control temperature of the temperature control platform 1 can not be obviously changed in one working mode.

In this embodiment, the semiconductor laser 3 is used to provide 976nm pump laser light that is absorbed by the gain cavity at a certain temperature point; 6 semiconductor lasers 3 are adopted, and any semiconductor laser 3 can be combined with the forward N +1 optical fiber beam combiner 4 if special application requirements exist; the number of pumps can be increased by adding a reverse optical fiber beam combiner according to the requirement; the semiconductor laser 3 with different wavelengths, such as 915nm, can also be selected according to different types of gain optical fibers and different application scenes; the semiconductor laser modules with various arbitrary wavelengths can be selected according to the characteristics of the gain medium, and are matched through different light spots under different cooling temperature settings;

in this embodiment, the N +1 optical fiber combiner 4 is configured to combine the N semiconductor lasers 3 into one optical fiber;

in this embodiment, the optical fiber gain cavity 5 includes a ytterbium-doped gain optical fiber 51, and a first grating 52 and a second grating 53 located at two ends of the ytterbium-doped gain optical fiber 51, an output end of the N +1 optical fiber combiner 4 is connected to the first grating 52, and an output end of the second grating 53 is connected to the optical fiber output cable 6. When the semiconductor laser 3 emits 976nm pump laser, the gain cavity absorbs the pump laser and performs gain amplification to generate gain laser (1070nm) transmitted by the fiber core, when the semiconductor laser 3 emits laser of other wave bands (such as above 985 nm), the gain cavity only absorbs a very small amount of pump laser, and the rest pump laser continues to be transmitted forwards along the gain cavity fiber; in the present application, the ytterbium-doped gain fiber 51 may design gain fibers with different lengths according to the absorption rate of the gain fiber to change the absorption saturation threshold, so that the laser outputs light spot beams of multiple modes;

in this embodiment, the optical fiber output cable 6 is a non-water-cooling QBH output cable, and is configured to transmit the laser beam generated or transmitted in the optical fiber gain cavity 5 to the surface of the workpiece;

in this embodiment, the phase-change type variable-frequency compression heat exchange system 7 is composed of a variable-frequency compressor, a condenser, an evaporator and an expansion valve, is used for providing temperature control with large temperature difference for the semiconductor laser, and can further comprise an electromagnetic four-way reversing valve, a variable-frequency fan, a refrigerant liquid storage tank and the like. Adopt electromagnetism four-way reversing valve can make the laser instrument possess and start and the ability of stable use in extremely cold environment, adopted single phase transition formula inverter compressor system to carry out temperature control to whole semiconductor laser in this embodiment, also can adopt multiunit phase transition formula inverter compressor system, carry out the temperature control of different temperatures respectively to multiple semiconductor laser, realize more various gain collocation.

The working principle is as follows:

when the temperature control system is used, the control system 2 sends corresponding instructions to the phase-change type variable-frequency compression heat exchange system 7 through the temperature control system 22 according to the working mode required by a user, the phase-change type variable-frequency compression heat exchange system 7 can operate at different powers according to different instructions and is connected with the temperature control platform 1 through a refrigerant flow channel, the temperature control platform 1 is subjected to temperature control at different temperatures, a temperature signal of the temperature control platform 1 is transmitted to the temperature control system 22 through the temperature monitoring system 23 in real time, and the temperature control system 22 can carry out variable-frequency regulation on the phase-change type variable-frequency compression heat exchange system 7 according to the feedback of the real-time temperature so as to ensure that the temperature of the temperature control platform 1 does not change obviously; the semiconductor laser 3 arranged on the temperature control platform 1 can be influenced by different cooling temperatures, so that the semiconductor laser 3 can also emit pumping laser with different wavelengths when the same current is supplied;

in some embodiments, the temperature control platform may further include a PTC heating tube for heating below a preset temperature so that the pump laser quickly reaches a predetermined temperature.

Working condition 1: when the temperature of the temperature control platform 1 is 20 ℃, the semiconductor laser 3 can emit 976nm pump laser, the pump laser is combined by the N +1 optical fiber combiner 4 and is conducted to the optical fiber gain cavity 5, the optical fiber gain cavity 5 can absorb and amplify the 976nm pump laser to 1070nm laser, and the laser is transmitted and output by the optical fiber output optical cable 6 to form a high-energy-density small-spot laser beam which is used for plate cutting, hand-held welding and other applications;

working condition 2: when the temperature of the temperature control platform 1 is 35 ℃, the refrigeration power is controlled to enable the pumping laser wavelength emitted by the semiconductor laser 3 to rise to above 985nm, the pumping laser is combined by the N +1 optical fiber combiner 4 and conducted into the optical fiber gain cavity 5, the optical fiber gain cavity 5 only absorbs a very small amount of pumping laser, most of the unabsorbed pumping laser is continuously transmitted forwards along the optical fiber cladding of the gain cavity and is transmitted and output by the optical fiber output optical cable 6 to form a large-spot laser beam with low energy density, and the large-spot laser beam can be used for cladding and other applications;

working mode 3: when the temperature of the temperature control platform 1 is 25 ℃, the pumping laser wavelength emitted by the semiconductor laser 3 is raised to 980nm, the pumping laser is combined by the N +1 optical fiber combiner 4 and is conducted into the optical fiber gain cavity 5, the optical fiber gain cavity 5 is in a semi-absorption state, namely only a part of the pumping laser is absorbed and amplified to 1070nm laser, the other part of the unabsorbed pumping laser is not absorbed by the optical fiber gain cavity 5, the laser amplified to 1070nm by gain and the unabsorbed pumping light are respectively transmitted forward along the fiber core and the cladding of the gain cavity optical fiber, and finally the laser is transmitted and output by the optical fiber output optical cable 6 to form a composite light spot beam with high central energy density and low peripheral energy density, which can be used for welding and other applications;

the system can enable the laser system to normally work without any water cooling system assistance, and can generate various laser matching output modes to adapt to different laser processing process requirements.

The system can be set to be in a frequency conversion mode through a refrigeration mode of the phase-change type frequency conversion compressor, and can carry out frequency conversion adjustment on the temperature of the temperature control platform in real time, so that the temperature control is more accurate; and controlling the output wavelength of the semiconductor laser by changing the temperature; the semiconductor can be ensured to work under a stable wavelength condition all the time; and can realize that a laser outputs multiple different beam modes, can realize the functions of high-density fiber laser, compound laser system and semiconductor laser respectively through single laser.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.