阅读说明：本技术 光检测器 (Light detector ) 是由 曹培炎 刘雨润 于 2018-02-03 设计创作，主要内容包括：本文所公开的是一种设备,包括：光源(102),配置成生成光脉冲,其中光脉冲的一个或多个属性按照第一代码来调制,光脉冲的一个或多个属性从由光脉冲的幅度、光脉冲之间的时间间隔、光脉冲的宽度、光脉冲的光谱及其组合所组成的组中选取；检测器(104),配置成接收包括目标场景(108)的一部分所散射的光脉冲的相应部分的光的混合,配置成基于第二代码从光的混合中选择光脉冲的部分,并且配置成基于光脉冲的部分的特性来生成电信号。(Disclosed herein is an apparatus comprising: a light source (102) configured to generate a light pulse, wherein one or more properties of the light pulse are modulated according to a first code, the one or more properties of the light pulse being selected from the group consisting of an amplitude of the light pulse, a time interval between the light pulses, a width of the light pulse, a spectrum of the light pulse, and combinations thereof; a detector (104) configured to receive a mixture of light including respective portions of the light pulses scattered by a portion of the target scene (108), configured to select portions of the light pulses from the mixture of light based on a second code, and configured to generate an electrical signal based on characteristics of the portions of the light pulses.)

1. An apparatus, comprising:

a light source configured to generate a light pulse, wherein one or more properties of the light pulse are modulated according to a first code, the one or more properties of the light pulse being selected from the group consisting of an amplitude of the light pulse, a time interval between the light pulses, a width of the light pulse, a spectrum of the light pulse, and combinations thereof;

a detector configured to receive a mixture of light comprising respective portions of the light pulses scattered by a portion of a target scene, configured to select the portion of the light pulses from the mixture of light based on a second code, and configured to generate an electrical signal based on a characteristic of the portion of the light pulses.

2. The apparatus of claim 1, wherein the light source is configured to vary a total radiant flux as a function of time based on the first code.

3. The apparatus of claim 1, wherein the light source is configured to change spectral flux as a function of time based on the first code.

4. The device of claim 1, wherein the light source is configured to change a proportion of total radiant flux in the light pulse as a function of time based on the first code.

5. The apparatus of claim 4, wherein the light source comprises a shutter and is configured to use the shutter to change the ratio.

6. The apparatus of claim 4, wherein the light source comprises one or more optical filters and is configured to use the one or more optical filters to change the ratio.

7. The apparatus of claim 1, wherein the detector is configured to select the portion of the light pulse by correlating the mixture of light with the second code.

8. The apparatus of claim 1, wherein the characteristic is time of flight.

9. The device of claim 1, wherein the light source comprises a light emitter and a light scanner, wherein the light scanner is configured to receive light from the light emitter and affect a direction of the light relative to the target scene.

10. The apparatus of claim 9, wherein the optical scanner comprises an optical waveguide and an electronic control system;

wherein the optical waveguide is configured to receive light from the light emitter;

the electronic control system is configured to adjust the dimensions of the optical waveguide by adjusting the temperature of the optical waveguide.

11. The apparatus of claim 10, wherein adjusting the temperature of the optical waveguide comprises applying a current through the optical waveguide.

12. The apparatus of claim 11, wherein at least one of the optical waveguides includes a conductive cladding around a core.

13. The apparatus of claim 12, wherein applying the current through the optical waveguide comprises applying the current through the conductive cladding.

14. The apparatus of claim 10, wherein the optical waveguide is formed on a surface of a substrate.

15. The apparatus of claim 10, wherein at least one of the optical waveguides is curved.

[ technical field ] A method for producing a semiconductor device

The present disclosure herein relates to optical detectors, and in particular to optical detectors with signal modulation.

[ background of the invention ]

Lidar is a laser-based detection, ranging, and mapping method. There are several main components of lidar systems: laser sources, scanners and optics, photodetectors, and receiver electronics. For example, controllable steering of the scanning laser beam is performed and by processing the captured return signals reflected from distant objects, buildings and landscapes, the distance and shape of these objects, buildings and landscapes can be derived.

Lidar systems are widely used. For example, autonomous vehicles (e.g., unmanned automobiles) use lidar (also known as vehicle-mounted lidar) for obstacle detection and collision avoidance to safely pass through the environment. The onboard lidar is mounted on the roof of an unmanned vehicle and it is constantly rotated to monitor the current environment around the vehicle. Lidar sensors provide the necessary data for software to determine where potential obstacles exist in the environment, help identify the spatial structure of the obstacle, distinguish objects based on size, and estimate the impact of travel on it. One advantage of lidar systems over radar systems is that lidar systems can provide better range and a large field of view, which helps detect obstacles on curved surfaces. Despite the tremendous advances in the development of lidar systems in recent years, there is still a great deal of work currently being done to design lidar systems for the needs of various applications, including the development of new light sources capable of performing controllable scanning and the development of new detectors capable of modulating optical pulse signals to account for light from different light sources.

[ summary of the invention ]

Disclosed herein is an apparatus comprising: a light source configured to generate a light pulse, wherein one or more properties of the light pulse are modulated according to a first code, the one or more properties of the light pulse being selected from the group consisting of an amplitude of the light pulse, a time interval between the light pulses, a width of the light pulse, a spectrum of the light pulse, and combinations thereof; a detector configured to receive a mixture of light including respective portions of the light pulses scattered by a portion of the target scene, configured to select portions of the light pulses from the mixture of light based on a second code, and configured to generate an electrical signal based on characteristics of the portions of the light pulses.

According to an embodiment, the light source is configured to change the total radiant flux as a function of time based on the first code.

According to an embodiment, the light source is configured to change the spectral flux as a function of time based on the first code.

According to an embodiment, the light source is configured to change the proportion of the total radiant flux in the light pulse as a function of time based on the first code.

According to an embodiment, the light source comprises a shutter and is configured to change the scale using the shutter.

According to an embodiment, the light source comprises one or more optical filters and is configured to change the scale using the one or more optical filters.

According to an embodiment, the detector is configured to select the portion of the light pulse by correlating the mixture of light with a second code.

According to an embodiment, the characteristic is time of flight.

According to an embodiment, the light source comprises a light emitter and a light scanner, wherein the light scanner is configured to receive light from the light emitter and to influence a direction of the light relative to the target scene.

According to an embodiment, an optical scanner includes an optical waveguide and an electronic control system; the optical waveguide is configured to receive light from the light emitter; the electronic control system is configured to adjust the dimensions of the optical waveguide by adjusting the temperature of the optical waveguide.

According to an embodiment, adjusting the temperature of the optical waveguide includes applying a current through the optical waveguide.

According to an embodiment, at least one of the optical waveguides comprises a conductive cladding around the core.

According to an embodiment, applying a current through the optical waveguide includes applying a current through the conductive cladding.

According to an embodiment, an optical waveguide is formed on a surface of a substrate.

According to an embodiment, at least one of the optical waveguides is curved.

[ description of the drawings ]

Fig. 1 schematically shows a perspective view of a device suitable for light emission, light modulation and detection according to an embodiment.

Fig. 2 schematically shows a functional block diagram of a light source according to an embodiment.

Fig. 3 and 4 each schematically show a functional block diagram of an alternative light source according to an embodiment.

FIG. 5 schematically illustrates a cross-sectional view of a detector having a light receiving assembly and a signal processor, in accordance with one embodiment.

Fig. 6 schematically shows a functional block diagram of a detector according to an embodiment.

FIG. 7A schematically illustrates a perspective view of a light directing assembly, in accordance with one embodiment.

FIG. 7B schematically illustrates a cross-sectional view of a light directing assembly, in accordance with one embodiment.

FIG. 7C schematically illustrates a cross-sectional view of a light directing assembly according to another embodiment.

Figure 7D schematically illustrates a cross-sectional view of a light directing assembly, in accordance with an embodiment.

[ detailed description ] embodiments

Fig. 1 schematically shows a device 100 suitable for light emission, modulation and detection according to an embodiment. The apparatus 100 may include a light source 102, a detector 104, and optics 106. The light source 102 may be configured to generate a pulse of light to illuminate a portion of the target scene 108. The portion of the target scene 108 may scatter the light pulses. One or more properties of the optical pulse may be modulated according to a first code. The one or more properties may be the amplitude of the light pulses, the time interval between the light pulses, the width of the light pulses, the spectrum of the light pulses, or a combination thereof.

The optical device 106 may be configured to affect (e.g., focus light pulses scattered by the portion of the target scene 108. the optical device 106 may be positioned between the detector 104 and the target scene 108.

The detector 104 may be configured to receive a mixture of light including portions of the light pulses scattered by the target scene 108. The mixture of light may include light that does not originate from the light source 102. The detector 104 may be configured to select a portion of the light pulse from the mixture of light based on the second code. In one embodiment, the detector 104 may be configured to generate an electrical signal based on characteristics of portions of the light pulses. An example of a characteristic is the time of flight of a light pulse from the light source 102 to the target scene 108 and back to the detector 104. The apparatus 100 may also include a signal processor 145 configured to process and analyze the electrical signals.

Fig. 2 schematically shows a functional block diagram of the light source 102 according to an embodiment. The light source 102 may be configured to generate the light pulse by changing the total radiant flux as a function of time based on the first code (as opposed to changing the proportion of the total radiant flux contained in the light pulse) or by changing the spectral flux as a function of time based on the first code. Light source 102 may include light emitter 202. Optical transmitter 202 may be a laser source. As shown in fig. 2, light source 102 may use controller 203 to change its total radiant flux (e.g., by changing the power provided to light emitter 202) or to change its spectral flux in accordance with a first code. The first code may be a fixed code specific to the light source 102 or may be adjustable. The controller 203 may include a TTL or other suitable emulation circuitry.

The light source 102 may include a light scanner 204. The optical scanner 204 may be configured to receive light from the light emitters 202 to affect the direction of (e.g., scanned) light relative to the target scene 108. For example, the light scanner 204 may scan light along the Y-dimension, as shown in FIG. 2. The light source 102 may include an optical component 206 configured to shape (e.g., diverge) light from the light scanner 204. As shown in fig. 2, an optical component 206 may be positioned between the optical scanner 204 and the target scene 108. Alternatively, the optical scanner 204 may be positioned between the optical assembly 206 and the target scene 108. In an embodiment, the optical component 206 may comprise a one-dimensional diffraction grating or a cylindrical lens.

Fig. 3 and 4 each schematically illustrate a functional block diagram of the light source 102 according to an embodiment. The light source 102 may be configured to generate the light pulse by varying a proportion of a total radiant flux in the light pulse as a function of time (as opposed to varying its total radiant flux) based on the first code. Light source 102 may include light emitter 202. Optical transmitter 202 may be a laser source. The total radiant flux of light emitter 202 may be constant. As shown in fig. 3, the light source 102 may use the shutter 207 to change the proportion of the total radiant flux in the light pulse according to a first code. For example, the ratio may be changed by opening or closing the shutter 207 in time series based on the first code. As shown in fig. 4, the light source 102 may use one or more optical filters 208 to vary the proportion of the total radiant flux in the light pulses according to a first code. For example, the proportions may be changed by changing the transmission spectra of the one or more optical filters 208 in a time series based on the first code.

The light source 102 may include a light scanner 204. The optical scanner 204 may be configured to receive light from the light emitters 202 to change the direction of (e.g., scan) the light relative to the target scene 108. For example, the optical scanner 204 may scan light along the Y-dimension, as shown in FIGS. 3 and 4. The light source 102 may include an optical component 206 configured to shape (e.g., diverge) light from the light scanner 204. As shown in fig. 3 and 4, a shutter 207 or one or more optical filters 208 may be positioned between the light scanner 204 and the light emitters 202. Alternatively, the shutter 207 or one or more optical filters 208 may be positioned at another suitable location along the optical path. In an embodiment, the optical component 206 may comprise a one-dimensional diffraction grating or a cylindrical lens.

The light source 102 may be configured to generate the light pulses by varying the total radiant flux as a function of time or by varying the proportion of the total radiant flux in the light pulses as a function of time.

Fig. 5 schematically shows a cross-sectional view of a detector 104 according to an embodiment. The detector may include a light receiving layer 151 and an electron layer 152. The light receiving layer 151 may be laminated on the electron shells 152. According to the embodiment, the plurality of light receiving members 140 are inside the light receiving layer 151. The light receiving component 140 may generate charge carriers when return light from the target scene 108 strikes the detector 104. The carriers may be directed (e.g., under an electric field) to the signal processor 145 in the electron shell 152.

Fig. 6 schematically shows a functional block diagram of the detector 104 according to an embodiment. The mixing of light comprising a portion of the light pulse modulated according to the first code and scattered by the portion of the target scene may generate carriers in the light receiving component 140. In embodiments, light receiving assembly 140 may include sub-assemblies configured to receive light of different spectral ranges (e.g., sub-assembly 140A is configured to receive light from λ 1- λ 2, sub-assembly 140B is configured to receive light from λ 3- λ 4, sub-assembly 140C is configured to receive light from λ 5- λ 6, etc.). The carriers may be converted into electrical signals, and the electrical signals may be processed by the signal processor 145. The signal processor 145 may include emulation circuitry (e.g., one or more analog-to-digital converters 330) configured to digitize the electrical signal. The detector 104 may select the portion of the light pulse from the mixture of light, for example, using the signal processor 145. The signal processor 145 may have a demodulator 340 configured to correlate the mixture of light (as represented by the electrical signal) with the second code with a varying delay between the mixture of light (as represented by the electrical signal) and the second code. The portion of the light pulse may be selected based on the result of the correlation. In an example, the result of the correlation is significant if and only if the delay between the portion of the light pulse and the second code is zero. A characteristic of the portion of the light pulse, such as time of flight, may be determined by a detector, such as by microprocessor 310 in signal processor 145, and stored in a memory or counter 320. The communication interface 350 may be included in the signal processor 145, and the communication interface 350 may be configured to communicate with other circuitry external to the signal processor 145 or external to the detector 104.

FIG. 7A schematically illustrates a perspective view of a light directing assembly 402, in accordance with one embodiment. The light directing assembly 402 may be an embodiment of the optical scanner 204 of the light source 102 and may include a plurality of optical waveguides 410 and an electronic control system 420. In one embodiment, a plurality of optical waveguides 410 may be located on a surface of substrate 430. The plurality of optical waveguides 410 may be controlled by the electronic control system 420 to generate a scanning beam and to direct the scanning beam in a second dimension.

Each of the optical waveguides 410 may include an input end 412, an optical core 414, and an output end 416. Optical core 414 may include an optical media. In one embodiment, the optical medium may be transparent. The input end 412 of the optical waveguide 410 may receive an input light wave, and the received light wave may pass through the optical core 414 and exit as an output light wave from the output end 416 of the optical waveguide 410. Diffraction may distribute the output light waves from each of the optical cores 414 over a wide angle such that when the input light waves are coherent (e.g., from a coherent light source such as a laser, etc.), the output light waves from the plurality of optical waveguides 410 may interfere with each other and exhibit an interference pattern. In one embodiment, the output ends 416 of the plurality of optical waveguides 410 may be arranged in a second dimension straight. For example, as shown in FIG. 7A, the output ends 416 of the plurality of optical waveguides 410 may be aligned along the Y-dimension. In this way, the output interface may face in the X direction.

The electronic control system 420 may be configured to control the phase of the output light waves from the plurality of optical waveguides 410 to obtain an interference pattern to generate a scanning beam, and to direct the scanning beam along the second dimension.

The dimensions of each of the optical cores 414 may be individually adjusted by the electronic control system 420 to control the phase of the output light waves from the respective optical core 414. The electronic control system 420 may be configured to individually adjust the dimensions of each of the optical cores 414 by individually adjusting the temperature of each of the optical cores 414.

In an embodiment, the optical waves of the input optical beams to the plurality of optical waveguides 410 may be at the same phase. The interference pattern of the output light waves from the plurality of optical waveguides 410 may include one or more propagating bright spots, where the output light waves constructively interfere (e.g., enhance), and one or more propagating weak spots, where the output light waves destructively interfere (e.g., cancel each other). In an embodiment, one or more propagating bright spots may form one or more scanning beams. If the phases of the output beams of the optical core 414 are shifted and the phase differences vary, constructive interference may occur in different directions, such that the interference pattern of the output optical waves (e.g., the direction of the generated scanning beam or beams) may also vary. In other words, the optical beams directed in the second dimension may be achieved by adjusting the phase of the output optical beams from the plurality of optical waveguides 410.

One way to adjust the phase of the output light wave is to change the effective optical path of the light wave propagating through the optical core 414. The effective optical path of a light wave propagating through an optical medium depends on the physical distance the light propagates in the optical medium (e.g., on the angle of incidence of the light wave, the dimensions of the optical medium). Accordingly, the electronic control system 420 may adjust the dimensions of the optical core 414 to change the effective optical path of the incident light beam propagating through the optical core 414 such that the phase of the output light wave may be shifted under the control of the electronic control system 420. For example, the length of each of the optical cores 414 may vary because at least a portion of the respective optical core 414 has a temperature change. Further, if at least a portion of at least a section of the optical core 414 has a temperature change, the diameter of the section of the optical core 414 may change. Thus, in one embodiment, adjusting the temperature of each of the optical cores 414 may be used to control the dimensions of the optical cores 414 (e.g., due to thermal expansion or contraction of the optical cores 414).

It should be noted that although fig. 7A shows a plurality of optical waveguides 410 arranged in parallel, this is not required in all embodiments. In some embodiments, the output ends 416 may be aligned along a certain dimension, but the plurality of optical waveguides 410 need not be straight or arranged in parallel. For example, in one embodiment, at least one of the optical waveguides 410 may be curved (e.g., "U" -shaped, "S" -shaped, etc.). The cross-sectional shape of the optical waveguide 410 may be rectangular, circular, or any other suitable shape. In an embodiment, the plurality of optical waveguides 410 may form a one-dimensional array, which is placed on the surface of the substrate 430 as shown in FIG. 7A. The optical waveguides 410 need not be uniformly distributed in a one-dimensional array. In other embodiments, the plurality of optical waveguides 410 need not be on one substrate. For example, some of the optical waveguides 410 may be on one substrate and some of the other optical waveguides 410 may be on a separate substrate.

Substrate 430 may include conductive, non-conductive, or semiconductor materials. In an embodiment, the substrate 430 may comprise a material such as silicon dioxide. In an embodiment, the electronic control system 420 may be embedded in the substrate 430, but may also be placed outside the substrate 430.

In an embodiment, the light source 102 may also include a beam expander (e.g., a set of lenses). The beam expander may expand the input optical beam before the input optical beam enters the plurality of optical waveguides 410. The expanded input beam may be collimated. In an embodiment, the light source 102 may also include a one-dimensional diffraction grating (e.g., a cylindrical microlens array) configured to converge and couple the light waves of the input light beam into the plurality of optical waveguides 410.

FIG. 7B schematically illustrates a cross-sectional view of the light directing assembly 402 of FIG. 7A, in accordance with one embodiment. Each of optical cores 414 may include an optical medium that is electrically conductive and transparent. The optical core 414 may be electrically connected to the electronic control system 420. In an embodiment, the electronic control system 420 may be configured to individually adjust the dimensions of each of the optical cores 414 by individually adjusting the temperature of each of the optical cores 414. The electronic control system 420 may apply electrical current to each of the optical cores 414 separately. The temperature of each of the optical cores 414 may be individually adjusted by controlling the magnitude of the current flowing through each of the optical cores 414.

FIG. 7C schematically illustrates a cross-sectional view of the light directing assembly 402 of FIG. 7A, in accordance with one embodiment. Each of the optical waveguides 410 may include a conductive cladding 418 around the sidewalls of the respective optical core 414. In an embodiment, each of the conductive coatings 418 may be electronically connected to an electronic control system 420. The electronic control system 420 may be configured to individually adjust the dimensions of each of the optical cores 414 by adjusting the temperature of each of the optical cores 414. The electronic control system 420 may apply an electrical current to each of the conductive coatings 418. Due to the heat transfer between the optical cores 414 and the respective conductive cladding 418, the temperature of each of the optical cores 414 may be individually adjusted by controlling the magnitude of each of the currents flowing through each of the respective conductive cladding 418.

FIG. 7D schematically illustrates a cross-sectional view of the light directing assembly 402 of FIG. 7A, in accordance with another embodiment. The light directing assembly 402 may include one or more temperature modulating assemblies. The temperature modulating component may convert a voltage or current input into a temperature differential, which may be used for heating or cooling. For example, the temperature modulating component may be a peltier device. One or more temperature modulating components may be capable of transferring heat to the plurality of optical waveguides 410. In an embodiment, one or more temperature modulating components may be in contact with the plurality of optical waveguides 410. In an embodiment, one or more temperature modulating components are electronically connected to the electronic control system 420. The electronic control system 420 may be configured to control the temperature of the at least one optical core 414 by adjusting the temperature of the one or more temperature modulating components due to heat transfer between the plurality of optical waveguides 410 and the one or more temperature modulating components. In one embodiment, one or more temperature modulating components may share a common substrate with multiple optical waveguides 410. In the example of FIG. 7D, light directing assembly 402 includes layer 422, which includes one or more temperature modulating assemblies on the surface of substrate 430, and layer 422 is in contact with the plurality of optical waveguides 410.

While various aspects and embodiments are disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.