Laser radar receiving system and laser radar

Abstract

The embodiment of the invention relates to the field of laser radars, and provides a laser radar receiving system and a laser radar. The laser radar receiving system comprises a substrate, a light guiding module, a light amplifier, a photon integrated circuit board and a photoelectric conversion module. The optical guiding module comprises a first optical waveguide, an input coupling grating, a second optical waveguide and an output coupling grating. The photon integrated circuit board is arranged on the substrate, and the light guiding module and the light amplifier are integrated on the photon integrated circuit board and located on the side, away from the substrate, of the photon integrated circuit board. An incident first optical signal sequentially passes through the input coupling grating and the first optical waveguide to reach the optical amplifier and is amplified into a second optical signal by the optical amplifier, and the second optical signal passes through the second optical waveguide and the output coupling grating to reach the photoelectric conversion module. The photoelectric conversion module is used for receiving the second optical signal and converting the optical signal into an electric signal.

Description

Technical Field

[0001] This application relates to the field of lidar, and particularly to a lidar receiving system and a lidar. Background Art

[0002] When a lidar receives the light energy reflected by an object in the laser optical path, due to the object being too far away or the reflectivity of the object being too low, the light energy reflected back to the lidar is too low, which will cause problems such as a shortened detection range and reduced accuracy of the lidar. If the light energy reflected back to the lidar is to be amplified, many amplifier circuit components or beam shaping components need to be added to improve the receiving performance of the lidar. The addition of these components will cause the lidar to be too large in size. Summary of the Invention

[0003] In a first aspect of this application, a lidar receiving system is provided, including:

[0004] A substrate;

[0005] An optical guiding module, including a first optical waveguide, an input coupling grating, a second optical waveguide, and an output coupling grating. The input coupling grating is used to receive a first optical signal and couple the first optical signal into the first optical waveguide, and the first optical waveguide is used to transmit the first optical signal;

[0006] An optical amplifier, which is used to receive the first optical signal and amplify the first optical signal into a second optical signal. The optical intensity of the second optical signal is greater than that of the first optical signal. The second optical waveguide is used to transmit the second optical signal to the output coupling grating, and the output coupling grating is used to couple and emit the second optical signal;

[0007] A photonic integrated circuit board, disposed on the substrate. The optical guiding module and the optical amplifier are integrated on the photonic integrated circuit board and are located on the side of the photonic integrated circuit board away from the substrate; and

[0008] A photoelectric conversion module, which is used to receive the second optical signal and convert the optical signal into an electrical signal.

[0009] For the lidar receiving system provided by the embodiments of this application, the optical guiding module and the optical amplifier are integrated on the photonic integrated circuit board, and the optical guiding module is processed on the photonic integrated circuit board by an etching method, so as to achieve a small-size and ultra-compact structure of the lidar receiving system, thereby further reducing the volume of the lidar receiving system.

[0010] In one embodiment, a first focusing lens is further provided in the photonic integrated circuit board. The first focusing lens is located on the optical path of the second optical signal and is configured to converge the second optical signal emitted from the output coupling grating onto the photoelectric conversion module. The lidar receiving system provided by the embodiment of the present application improves the reception rate of the photoelectric conversion module and reduces the loss of the lidar receiving system by providing a first focusing lens on the photonic integrated circuit board to converge the second optical signal emitted from the output coupling grating onto the photoelectric conversion module.

[0011] In one embodiment, the photoelectric conversion module is disposed on a side of the substrate close to the photonic integrated circuit board. The photoelectric conversion module includes a light receiving surface. The light receiving surface is disposed on a side of the first focusing lens close to the substrate. The photoelectric conversion module is electrically connected to the substrate.

[0012] In one embodiment, the photoelectric conversion module is disposed on a side of the photonic integrated circuit board away from the substrate. The photoelectric conversion module and the optical guiding module are disposed on the same side of the photonic integrated circuit board. The photoelectric conversion module includes a light receiving surface. The light receiving surface is directly above a side of the output coupling grating away from the substrate. The light receiving surface is configured to receive the second optical signal coupled and emitted from the output coupling grating. The photoelectric conversion module is electrically connected to the photonic integrated circuit board. The lidar receiving system provided by the embodiment of the present application is conducive to reducing the production difficulty in the actual production process and thus improving the production efficiency by disposing the photoelectric conversion module on the photonic integrated circuit board.

[0013] In one embodiment, the photoelectric conversion module includes an avalanche photodiode. The avalanche photodiode receives the second optical signal transmitted by the output coupling grating and converts the second optical signal into an electrical signal. The lidar receiving system provided by the embodiment of the present application needs to detect light with a wavelength of 1550 nm. By using an avalanche photodiode with a receiving wavelength range of 900 - 1700 nm, the requirements of the embodiment of the present application can be met.

[0014] In one embodiment, the lidar receiving system further includes a housing. The housing covers a side of the photonic integrated circuit board away from the substrate and covers the regions of the optical guiding module and the optical amplifier. The lidar receiving system provided by the embodiment of the present application can effectively protect the optical guiding module and the optical amplifier and enhance the stability of the lidar receiving system by providing a housing in the lidar receiving system to seal the optical guiding module and the optical amplifier in the housing.

[0015] In one embodiment, the optical guiding module further includes a second focusing lens, which is configured to receive the first optical signal and converge and emit the first optical signal onto the input coupling grating. The lidar receiving system provided by the embodiments of the present application can converge the first optical signal received from the outside by providing a second focusing lens in the lidar receiving system, improving the light receiving rate of the lidar receiving system and reducing unnecessary losses of the first optical signal.

[0016] In one embodiment, both the first optical waveguide and the second optical waveguide are disposed on a surface of the photon integrated circuit board away from the substrate. The first optical waveguide is disposed between the input coupling grating and the optical amplifier, and the output coupling grating is also disposed between the optical amplifier and the input coupling grating. Both the first optical waveguide and the second optical waveguide are located between the optical amplifier and the input coupling grating.

[0017] In one embodiment, the first optical waveguide is disposed between the input coupling grating and the optical amplifier, the output coupling grating is disposed at an end of the optical amplifier away from the input coupling grating, and the second optical waveguide is disposed between the optical amplifier and the output coupling grating.

[0018] In one embodiment, the optical amplifier includes an antireflection film disposed on two end faces of the optical amplifier for receiving the first optical signal and emitting the second optical signal. The antireflection film is configured to reduce reflection of the second optical signal on the two end faces. The lidar receiving system provided by the embodiments of the present application reduces losses during the amplification process while amplifying the first optical signal into the second optical signal by providing an antireflection film on the end faces of the optical amplifier, improving the utilization rate of light.

[0019] The second aspect of the present application provides a lidar, including:

[0020] A light source configured to emit detection light, where the detection light reflects a first optical signal after encountering an external object; and the above-described lidar receiving system configured to receive the first optical signal.

[0021] The lidar provided by the embodiments of the present application has the lidar receiving system described in the first aspect, and thus also has the same beneficial effects, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a front view schematic diagram of the structure of the lidar receiving system according to Embodiment 1 of the present application.

[0023] Figure 2 It is a schematic diagram of the structure of the optical amplifier according to Embodiment 1 of the present application.

[0024] Figure 3 It is a partial structure top view schematic diagram of the lidar receiving system according to the first embodiment of the present application.

[0025] Figure 4 It is a front view schematic diagram of the lidar receiving system structure according to the modified first embodiment of the present application.

[0026] Figure 5 It is a partial structure top view schematic diagram of the lidar receiving system according to the modified first embodiment of the present application.

[0027] Figure 6 It is a schematic diagram of the lidar receiving system structure according to the second embodiment of the present application.

[0028] Figure 7 It is a schematic diagram of the lidar structure according to the third embodiment of the present application.

[0029] Description of main element symbols:

[0030] Lidar receiving systems 100, 200

[0031] Substrate 1

[0032] Optical guiding module 2

[0033] First optical waveguide 20

[0034] Input coupling grating 21

[0035] Second optical waveguide 23

[0036] Output coupling grating 25

[0037] Second focusing lens 27

[0038] Optical amplifier 3

[0039] Antireflection film 30

[0040] End face 31

[0041] Input end 33

[0042] Output end 35

[0043] Photonic integrated circuit board 4

[0044] First focusing lens 40

[0045] Photoelectric conversion module 5

[0046] Light receiving surface 50

[0047] Avalanche photodiode 51

[0048] Housing 7

[0049] Cavity 9

[0050] LiDAR 300

[0051] Light source 301

[0052] Collimation module 303

[0053] Optical phased array module 305

[0054] Controller 307

[0055] External object 309

[0056] Transimpedance amplifier 311

[0057] Analog-to-digital converter 313

[0058] Detection light L0

[0059] First optical signal L1

[0060] Second optical signal L2

[0061] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific embodiments

[0062] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0063] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application.

[0064] In order to further elaborate on the technical means and effects adopted by the present application to achieve the predetermined purpose, the following detailed description of the present application is made in conjunction with the accompanying drawings and preferred embodiments.

[0065] Embodiment 1

[0066] Please refer to Figure 1, the lidar receiving system 100 provided in this embodiment includes: a substrate 1, an optical guiding module 2, an optical amplifier 3, a photonic integrated circuit board 4, and a photoelectric conversion module 5. The optical guiding module 2 includes a first optical waveguide 20, an input coupling grating 21, a second optical waveguide 23, and an output coupling grating 25. The input coupling grating 21 is used to receive the first optical signal L1 and couple the first optical signal L1 into the first optical waveguide 20, and the first optical waveguide 20 is used to transmit the first optical signal L1 to the optical amplifier 3. The optical amplifier 3 is used to receive the first optical signal L1 emitted from the first optical waveguide 20 and amplify the first optical signal L1 into a second optical signal L2, and the optical intensity of the second optical signal L2 is greater than that of the first optical signal L1. The second optical waveguide 23 is used to transfer the second optical signal L2 to the output coupling grating 25, and the output coupling grating 25 is used to couple and emit the second optical signal L2. The photonic integrated circuit board 4 is disposed on the substrate 1, and the optical guiding module 2 and the optical amplifier 3 are integrated on the photonic integrated circuit board 4 and located on the side of the photonic integrated circuit board 4 away from the substrate 1. The photoelectric conversion module 5 is used to receive the second optical signal L2 and convert the optical signal into an electrical signal. The lidar receiving system 100 provided in this embodiment integrates the optical guiding module 2 and the optical amplifier 3 on the photonic integrated circuit board 4, and processes the optical guiding module 2 on the photonic integrated circuit board 4 by an etching method, so as to realize a small-size and ultra-compact structure of the lidar receiving system 100, thereby further reducing the volume of the lidar receiving system 100.

[0067] In this embodiment, the first optical signal L1 is derived from a lidar transmitting system, and the wavelength of the first optical signal L1 includes 1550 nm. After the lidar transmitting system emits the detection light into free space, an external object in the free space reflects the detection light to form the first optical signal L1, and the first optical signal L1 can be received by the lidar receiving system 100. In other embodiments, the first optical signal L1 may also be derived from a mounted lidar detection and ranging system installed on an airplane, an automobile, and a ship. After the mounted lidar detection and ranging system emits the detection light into free space, the receiving system of the mounted lidar detection and ranging system can also receive the first optical signal L1 formed after the detection light is reflected.

[0068] In one embodiment, the size of the photonic integrated circuit board 4 is a square of 2 cm × 2 cm, and the base material of the photonic integrated circuit board 4 is silicon. Using silicon as the base material of the photonic integrated circuit board 4 has the advantages of high conductivity and low cost. Since the base material of the photonic integrated circuit board 4 depends on the overall application environment of the photonic integrated circuit, in other embodiments, the base material of the photonic integrated circuit board 4 may also be indium phosphide, silicon nitride, or silicon-based optoelectronics, which is not limited in this application.

[0069] The photon integrated circuit board 4 is further provided with a first focusing lens 40. The first focusing lens 40 is located on the optical path of the second optical signal L2 and is used to converge the second optical signal L2 emitted from the output coupling grating 25 onto the photoelectric conversion module 5. In one embodiment, the first focusing lens 40 may be a convex mirror, and the convex surface of the convex mirror faces the substrate 1 side. In other embodiments, the first focusing lens 40 may also be a Fresnel lens, and the surface of the Fresnel lens is etched with minute stepped structures for gathering the second optical signal L2. By providing the first focusing lens 40 on the photon integrated circuit board 4, the second optical signal L2 emitted from the output coupling grating 25 is converged onto the photoelectric conversion module 5, improving the reception rate of the photoelectric conversion module and reducing the loss of the lidar receiving system 100.

[0070] Please refer to Figure 2 , in this embodiment, the optical amplifier 3 includes an antireflection film 30. The antireflection film 30 is disposed on the two end faces 31 of the optical amplifier 3 for receiving the first optical signal L1 and emitting the second optical signal L2. The antireflection film 30 is used to reduce the reflection of the second optical signal L2 on the two end faces 31. By providing the antireflection film 30 on the end faces 31 of the optical amplifier 3, while amplifying the first optical signal L1 into the second optical signal L2, the loss during the amplification process is reduced and the utilization rate of light is improved.

[0071] Please refer to together Figure 1 and Figure 3 , in this embodiment, both the first optical waveguide 20 and the second optical waveguide 23 are disposed on the surface of the photon integrated circuit board 4 away from the substrate 1. The first optical waveguide 20 is coupled to the input end 33 of the optical amplifier 3, and the second optical waveguide 23 is coupled to the output end 35 of the optical amplifier 3. The first optical waveguide 20 is disposed between the input coupling grating 21 and the optical amplifier 3. Since the output coupling grating 25 is also disposed between the optical amplifier 3 and the input coupling grating 21, that is, both the first optical waveguide 20 and the second optical waveguide 23 are located between the optical amplifier 3 and the input coupling grating 21. Figure 3 is a partial structure top view schematic diagram of the lidar receiving system according to the first embodiment of the present application. To better present the positions of the first optical waveguide 20 and the second optical waveguide 23 in this embodiment, the housing, the substrate, the second focusing lens, etc. are not shown in the figure. The extending paths of the first optical waveguide 20 and the second optical waveguide 23 may be regular straight lines or irregular curves, which are not limited in the present application.

[0072] Please refer to Figure 4 and Figure 5, in other embodiments, the first optical waveguide 20 and the second optical waveguide 23 are also both disposed on the surface of the photon integrated circuit board 4 away from the substrate 1. The first optical waveguide 20 is disposed between the input coupling grating 21 and the optical amplifier 3. Since the output coupling grating 25 is disposed at one end of the optical amplifier 3 away from the input coupling grating 21 at this time, that is, the second optical waveguide 23 is located between the optical amplifier 3 and the output coupling grating 25. At this time, the first optical waveguide 20 and the second optical waveguide 23 are respectively coupled to the input end 33 and the output end 35 of the optical amplifier 3, and the output end 35 and the output end 35 of the optical amplifier 3 are disposed on different sides of the optical amplifier 3. Figure 5 This is a partial top view schematic diagram of the lidar receiving system according to the first modified embodiment of the present application. To better present the positions of the first optical waveguide 20 and the second optical waveguide 23 in this embodiment, the housing, the substrate, the second focusing lens, etc. are not shown in the figure. In this embodiment, since the first optical waveguide 20 and the second optical waveguide 23 are disposed on different sides of the optical amplifier 3, the processing difficulty can be reduced during etching microfabrication, and this setting method can improve the processing efficiency in the actual production process.

[0073] The preparation process of the first optical waveguide 20 and the second optical waveguide 23 generally requires two processes. First, an optical waveguide thin film is fabricated on the surface of the photon integrated circuit board 4 away from the substrate 1 by using atomic doping technology, deposition technology, epitaxial growth technology or electro-optic technology. Then, an optical guiding module 2 and the integrated optical amplifier 3 are fabricated on the optical waveguide thin film by chemical etching or ion beam etching to finally form a photon integrated circuit.

[0074] Please refer to Figure 1 , in this embodiment, the photoelectric conversion module 5 is disposed on the side of the substrate 1 close to the photon integrated circuit board 4. The photoelectric conversion module 5 includes a light receiving surface 50 for receiving the second optical signal L2 coupled out from the output coupling grating 25. The light receiving surface 50 is disposed on the side of the first focusing lens 40 close to the substrate 1. When the second optical signal L2 is incident on the photoelectric conversion module, the second optical signal L2 is received by the light receiving surface 50 of the photoelectric conversion module 5, and a photocurrent is formed after the second optical signal L2 is absorbed. At this time, the optical signal is converted into an electrical signal. The photoelectric conversion module 5 is electrically connected to the substrate 1.

[0075] In this embodiment, the photoelectric conversion module 5 includes an avalanche photodiode 51. The avalanche photodiode 51 receives the second optical signal L2 transmitted by the output coupling grating 25 and converts the second optical signal L2 into an electrical signal. By using the avalanche photodiode 51, light in the wavelength range of 900 - 1700 nm can be received, meeting the requirement that the lidar receiving system 100 in this embodiment needs to detect light with a wavelength of 1550 nm. In other embodiments, different photoelectric conversion modules 5 can also be selected according to the wavelength of the light wave to be detected. For example, silicon photomultipliers and single-photon avalanche devices can be selected, and this application is not limited.

[0076] The substrate 1 is a printed circuit board made of organic materials (such as phenolic resin, glass fiber / epoxy resin, and polyimide, etc.) or inorganic materials (such as aluminum or ceramic, etc.). The substrate 1 is connected to the photon integrated circuit board 4 by means of soldering or bonding. The substrate 1 is provided with circuit traces. In this embodiment, there is an electrical connection between the substrate 1 and the photon integrated circuit board 4 for supplying power to the optical amplifier 3. There is also a cavity 9 between the substrate 1 and the photon integrated circuit board 4. The cavity 9 is arranged directly below the output coupling grating 25, and the cavity 9 is used to accommodate the above-mentioned photoelectric conversion module, reducing the difficulty of aligning the photoelectric conversion module 5 with the output coupling grating 25 during actual processing.

[0077] Please continue to refer to Figure 1 , the lidar receiving system 100 further includes a housing 7. The housing 7 covers the side of the photon integrated circuit board 4 away from the substrate 1 and covers the areas of the optical guiding module 2 and the optical amplifier 3. The housing 7 is used to seal the optical guiding module 2 and the optical amplifier 3. In this embodiment, the housing 7 can provide a vacuum or a protective gas-filled environment for the lidar receiving system 100. Chemically stable gases such as helium (He), neon (Ne), and argon (Ar) can be filled in the housing 7 to protect the lidar receiving system 100, thereby extending the lifespan and usage duration of the lidar receiving system 100. The housing 7 seals the optical guiding module 2 and the optical amplifier 3 in the housing 7, which can effectively protect the optical guiding module 2 and the optical amplifier 3 and enhance the stability of the lidar receiving system 100.

[0078] The optical guiding module 2 further includes a second focusing lens 27. The second focusing lens 27 is configured to receive the first optical signal L1 and converge and emit the first optical signal L1 to the input coupling grating 21. The second focusing lens 27 is supported by the housing 7. In one embodiment, the second focusing lens 27 is adhesively disposed on the opening of the housing 7 by an adhesive bonding method. In other embodiments, the second focusing lens 27 and the housing 7 may also be integrally formed by a processing method using a glass material or a resin material, which is not limited in this application. By providing the second focusing lens 27, it is beneficial to improve the light reception rate of the lidar receiving system 100 and reduce unnecessary losses of the first optical signal L1.

[0079] Embodiment 2

[0080] Please refer to Figure 6 , the difference between the lidar receiving system 200 provided in this embodiment and the lidar receiving system 100 in Embodiment 1 is that the optoelectronic conversion module 5 is disposed on the side of the photon integrated circuit board 4 away from the substrate 1, that is, the optoelectronic conversion module 5 and the optical guiding module 2 are disposed on the same side of the photon integrated circuit board 4. The optoelectronic conversion module 5 includes a light receiving surface 50. The light receiving surface 50 is located directly above the output coupling grating 25 on the side away from the substrate 1. The light receiving surface 50 is configured to receive the second optical signal L2 coupled and emitted from the output coupling grating 25. The optoelectronic conversion module 5 is electrically connected to the photon integrated circuit board 4. In this embodiment, the substrate 1 is a printed circuit board, which plays a role of supporting and fixing the entire lidar receiving system 200. By disposing the optoelectronic conversion module 5 on the photon integrated circuit board 4 in the lidar receiving system 200 provided in this embodiment, it is beneficial to reduce the production difficulty in the actual production process, thereby improving the production efficiency.

[0081] Embodiment 3

[0082] The lidar 300 provided in this embodiment, please refer to Figure 7, comprising: a light source 301 and the lidar receiving system 100(200) of any of the above embodiments. The light source 301 is configured to emit a detection light L0, and the detection light L0 reflects a first optical signal L1 after encountering an external object 309. The lidar receiving system 100(200) is configured to receive the first optical signal L1. Specifically, after the light source 301 emits the detection light L0, it first passes through a collimation module 303, and the collimation module 303 is configured to focus and collimate the detection light L0 emitted by the light source 301. The detection light L0 then passes through an optical phased array module 305. The optical phased array module 305 is electrically connected to a controller 307, and the controller 307 is configured to provide a detection signal for controlling the detection range of the detection light L0. The optical phased array module 305 is configured to control the scanning direction of the detection light L0 beam. After the detection light L0 exits from the optical phased array module 305 into free space, it is reflected by the external object 309 to form a first optical signal L1, and the lidar receiving system 100(200) receives the first optical signal L1 reflected back by the external object 309. The lidar receiving system 100(200) amplifies the first optical signal L1 into a second optical signal (not shown in the figure) and converts the second optical signal (not shown in the figure) from an optical signal into an electrical signal, and the electrical signal at this time is a current signal. The current signal then passes through a transimpedance amplifier 311, and the transimpedance amplifier 311 is configured to receive the current signal transmitted by a photoelectric conversion module (not shown in the figure) and amplify the current signal into a voltage signal. The voltage signal finally passes through an analog-to-digital converter 313, and the analog-to-digital converter 313 is configured to convert a continuous analog signal into a discrete digital signal, so as to facilitate signal processing and data conversion, and facilitate computer control and calculation. The lidar 300 provided in this embodiment has the above lidar receiving system 100(200), so it also has the same beneficial effects, which will not be elaborated here.

[0083] Those of ordinary skill in the art of this technology should recognize that the above embodiments are only used to illustrate the present application, rather than to limit the present application. As long as within the scope of the spirit of the present application, appropriate changes and variations made to the above embodiments fall within the scope of protection required by the present application.

Claims

1. A lidar receiving system, characterized in that, Comprising: A substrate; An optical guiding module, including a first optical waveguide, an input coupling grating, a second optical waveguide, and an output coupling grating. The input coupling grating is configured to receive a first optical signal and couple the first optical signal into the first optical waveguide, and the first optical waveguide is configured to transmit the first optical signal; An optical amplifier, which is configured to receive the first optical signal and amplify the first optical signal into a second optical signal. The optical intensity of the second optical signal is greater than that of the first optical signal. The second optical waveguide is configured to transmit the second optical signal to the output coupling grating, and the output coupling grating is configured to couple and output the second optical signal; A photonic integrated circuit board disposed on the substrate. The optical guiding module and the optical amplifier are integrated on the photonic integrated circuit board and located on the side of the photonic integrated circuit board away from the substrate; And A photoelectric conversion module, which is configured to receive the second optical signal and convert the optical signal into an electrical signal.

2. The lidar receiving system according to claim 1, characterized in that, A first focusing lens is further disposed in the photonic integrated circuit board. The first focusing lens is located on the optical path of the second optical signal and is configured to converge the second optical signal output from the output coupling grating onto the photoelectric conversion module.

3. The lidar receiving system according to claim 2, characterized in that The photoelectric conversion module is disposed on the side of the substrate close to the photonic integrated circuit board. The photoelectric conversion module includes a light receiving surface, and the light receiving surface is disposed on the side of the first focusing lens close to the substrate. The photoelectric conversion module is electrically connected to the substrate.

4. The lidar receiving system according to claim 1, wherein The photoelectric conversion module is disposed on the side of the photonic integrated circuit board away from the substrate. The photoelectric conversion module and the optical guiding module are disposed on the same side of the photonic integrated circuit board. The photoelectric conversion module includes a light receiving surface, and the light receiving surface is directly above the side of the output coupling grating away from the substrate. The light receiving surface is configured to receive the second optical signal coupled and output from the output coupling grating. The photoelectric conversion module is electrically connected to the photonic integrated circuit board.

5. The lidar receiving system according to claim 1, wherein The photoelectric conversion module includes an avalanche photodiode, which receives the second optical signal transmitted by the output coupling grating and converts the second optical signal into an electrical signal.

6. The lidar receiving system according to claim 1, wherein The lidar receiving system further includes a housing, and the housing covers the side of the photonic integrated circuit board away from the substrate and covers the area where the optical guiding module and the optical amplifier are disposed.

7. The lidar receiving system according to claim 6, wherein The optical guiding module further includes a second focusing lens, which is configured to receive the first optical signal and converge and output the first optical signal to the input coupling grating.

8. The lidar receiving system according to claim 1, wherein, Both the first optical waveguide and the second optical waveguide are disposed on the surface of the photonic integrated circuit board away from the substrate. The first optical waveguide is disposed between the input coupling grating and the optical amplifier, and the output coupling grating is also disposed between the optical amplifier and the input coupling grating. Both the first optical waveguide and the second optical waveguide are located between the optical amplifier and the input coupling grating.

9. The lidar receiving system according to claim 1, characterized in that, The first optical waveguide is disposed between the input coupling grating and the optical amplifier, the output coupling grating is disposed at an end of the optical amplifier away from the input coupling grating, and the second optical waveguide is disposed between the optical amplifier and the output coupling grating.

10. The lidar receiving system according to claim 1, characterized in that, The optical amplifier includes an antireflection film, and the antireflection film is disposed on two end faces of the optical amplifier for receiving the first optical signal and emitting the second optical signal, and the antireflection film is used for reducing the reflection of the second optical signal on the two end faces.

11. A lidar, characterized in that, Comprising: A light source for emitting a detection light, and the detection light reflects a first optical signal after encountering an external object; And The lidar receiving system according to any one of claims 1-10, for receiving the first optical signal.

Images