Receiving assembly and lidar

Abstract

The present application discloses a receiving assembly and a lidar. The receiving assembly comprises a scanning device and at least one receiving channel; each receiving channel comprises at least one receiving waveguide and at least one grating coupler; the receiving waveguides are in one-to-one correspondence with the grating couplers; the grating couplers are used for coupling received light, which is reflected back by the scanning device, into the corresponding receiving waveguides; each grating coupler comprises a first grating layer; the first grating layer comprises a plurality of grating units arranged in a first direction; the duty ratio of each grating unit among the plurality of grating units is within a first range; the total length of the plurality of grating units in the first direction is greater than a first length; and the first direction corresponds to the scanning direction of the scanning device. The receiving assembly uses the grating couplers to couple the received light into the corresponding receiving waveguides, thereby improving the receiving efficiency of the lidar, and reducing the hardware cost and product size of the lidar.

Description

A receiving component and laser radar

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on January 18, 2024, with application number 202410074100.2 and application name "A Receiving Component and LiDAR", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of detection technology, and in particular to a receiving component and a laser radar. Background Art

[0004] In laser radar, an edge coupler (EC) is generally used to couple the received light into the receiving waveguide.

[0005] To achieve a sufficient frequency, a laser radar is typically equipped with one or more rapidly rotating scanning devices, through which the transmitted light is emitted and the received light is returned. Since it takes a certain amount of time for the laser to be emitted, hit the target, and then be reflected from the target and received, and the scanning device has rotated a certain angle during this time, there will be a certain deflection angle between the transmitted and received light, resulting in an asynchronous transmission and reception effect (also known as the walk-off effect). The position of the offset received light on the receiving surface of the end coupler is offset from the ideal receiving position and may even move out of the receiving surface of the end coupler, resulting in low laser radar reception efficiency and poor detection performance.

[0006] One way to combat the walk-off effect is to increase the number of waveguides in each LiDAR receiving channel, forming a waveguide array to increase the equivalent receiving surface of the LiDAR's entire receiver. This allows the LiDAR to still detect optical signals even after the received light is offset. However, this approach not only increases costs exponentially but also places significant pressure on the back-end hardware signal processing. Furthermore, this approach can only improve light reception efficiency at specific offset angles when the offset direction of the received light is parallel to the arrangement direction of the multiple waveguides. Light reception efficiency at other offset angles remains poor. Furthermore, if multiple waveguides are combined into a single waveguide for reception, the combined output optical power is much lower than the input optical power, resulting in poor overall light reception efficiency.

[0007] How to improve the receiving efficiency of lidar while reducing the hardware cost and product size of lidar is a technical problem that needs to be solved urgently. Summary of the Invention

[0008] The present application provides a receiving component and a laser radar for improving the receiving efficiency of the laser radar while reducing the hardware cost and product size of the laser radar.

[0009] In a first aspect, a receiving component is provided that can be applied to a laser radar, the receiving component comprising a scanning device and at least one receiving channel; each receiving channel in the at least one receiving channel comprises at least one receiving waveguide and at least one grating coupler, the receiving waveguide and the grating coupler correspond one to one, and each grating coupler in the at least one grating coupler is used to couple the received light reflected back by the scanning device into the receiving waveguide corresponding to each grating coupler; wherein the grating coupler comprises a first grating layer, the first grating layer comprises a plurality of grating units arranged along a first direction, a duty cycle of each of the plurality of grating units is within a first range, a total length of the plurality of grating units in the first direction is greater than the first length, and the first direction corresponds to (for example, is parallel to) a scanning direction of the scanning device.

[0010] In the receiving component provided in the embodiment of the present application, a grating coupler is used to couple the received light into the receiving waveguide, wherein the duty cycle of each of the multiple grating units in the first grating layer of the grating coupler is within a first range, and the total length of the multiple grating units in the first direction is greater than the first length. In this way, the total length of the mode field (i.e., the effective receiving surface) of the grating coupler in the first direction is greater than the first length, so that the received light can be received by the grating coupler and coupled into the receiving waveguide even after being offset due to the walk-off effect, thereby improving (or solving) the problem of low receiving efficiency of the laser radar caused by the walk-off effect.

[0011] Moreover, in the embodiment of the present application, since the mode field of the grating coupler is large enough, a receiving channel can have at least a combination of only one receiving waveguide and one grating coupler, and there is no need to add an additional optical transposition system. Therefore, it is possible to improve the receiving efficiency of the laser radar while reducing the hardware cost and product size of the laser radar.

[0012] In addition, the position of the grating coupler is relatively flexible and can be located anywhere in the lidar chip, so it can minimize unnecessary cross-waveguide crossing and reduce crosstalk between waveguides, thereby improving the overall receiving performance of the lidar.

[0013] In a possible design, the first direction corresponds to (eg, is parallel to) a deflection direction of a walk-off effect generated by the scanning device.

[0014] Because the deflection direction of the walk-off effect is caused by the scanning of the scanning device, the first direction corresponds to the scanning direction of the scanning device, which can also be replaced by describing that the first direction corresponds to the deflection direction of the walk-off effect.

[0015] In one possible design, the grating period of each of the plurality of grating units is within a second range.

[0016] By designing the grating period of the grating coupler, the mode field of the grating coupler can be increased in the offset direction of the walk-off effect.

[0017] In one possible design, the length of the mode field of the grating coupler in the first direction is greater than the first length.

[0018] In this way, it can be ensured that the offset received light is still projected into the mode field of the grating coupler, thereby improving the receiving efficiency of the lidar.

[0019] In one possible design, the first length is related to a maximum offset corresponding to a walk-off effect generated by the scanning device.

[0020] In this way, when the walk-off effect is most severe, the offset received light can still be projected into the mode field of the grating coupler, thereby improving the receiving efficiency of the lidar.

[0021] In one possible design, the scanning device is a one-dimensional scanning device, and the first direction (or the offset direction of the walk-off effect generated by the scanning device) corresponds to (for example, is parallel to) the scanning direction of the scanning device; or, the scanning device is a two-dimensional scanning device, and the first direction (or the offset direction of the walk-off effect generated by the scanning device) corresponds to (for example, is parallel to) the scanning direction of the fast axis in the two-dimensional scanning device.

[0022] In this way, both a one-dimensional scanning device and a two-dimensional scanning device can improve (or solve) the problem of low receiving efficiency of the laser radar caused by the walk-off effect.

[0023] In one possible design, the total length of the plurality of grating units in the second direction is less than the first length, and the second direction is perpendicular to the first direction.

[0024] In this way, the mode field of the first grating layer (or grating coupler) can be increased in the offset direction of the walk-off effect, while it does not increase (or the increment is small) in the second direction. For example, the length of the mode field of the grating coupler in the second direction is smaller than the first length, thereby improving the receiving efficiency of the first grating layer (or grating coupler) while minimizing the size of the grating coupler.

[0025] In a possible design, a total length of the plurality of grating units in the second direction is equal to a total length of the plurality of grating units in the first direction, and the second direction is perpendicular to the first direction.

[0026] In this way, the mode field of the first grating layer (or grating coupler) can be increased in multiple directions (including the offset direction of the walk-off effect). For example, the length of the mode field of the grating coupler in the second direction is equal to the length of the mode field of the grating coupler in the first direction, further improving the receiving efficiency of the first grating layer (or grating coupler).

[0027] In one possible design, a first grating unit among the plurality of grating units is offset relative to a center of the plurality of grating units, and the offset direction of the first grating unit relative to the center is the same as the offset direction of a walk-off effect generated by a scanning device; wherein a duty cycle of the first grating unit is a first value, and a grating period of the first grating unit is a second value.

[0028] In this way, the mode field of the first grating layer (or grating coupler) can be a mode field with a peak value biased to one side, which can improve the receiving efficiency of the first grating layer (or grating coupler) for the offset received light.

[0029] In one possible design, the offset of the first grating unit relative to the center is related to the maximum offset corresponding to the walk-off effect generated by the scanning device.

[0030] In this way, when the walk-off effect is most severe (i.e., when the offset corresponding to the walk-off effect is the largest), the position of the received light is exactly the peak position, and the first grating layer (or grating coupler) has the highest receiving efficiency for the received light.

[0031] In a possible design, a first grating unit among the plurality of grating units is located at the center of the plurality of grating units; wherein a duty cycle of the first grating unit is a first value, and a grating period of the first grating unit is a second value.

[0032] In this way, the mode field of the first grating layer (or grating coupler) can be a mode field with a peak at the center, and the receiving efficiency of the position of the received light before the offset is higher.

[0033] In a possible design, the coupling efficiency of the first grating unit is a maximum value among the coupling efficiencies of the grating units in the plurality of grating units.

[0034] In one possible design, the duty cycle of each grating unit in the plurality of grating units increases or decreases successively from the first grating unit to the second grating unit; or, the coupling efficiency of each grating unit in the plurality of grating units decreases successively from the first grating unit to the second grating unit; wherein the second grating unit is the first grating unit or the last grating unit of the plurality of grating units in the first direction.

[0035] In this way, the mode field of the first grating layer (or grating coupler) can be a Gaussian spot mode field or a Gaussian-like spot mode field. When the spot of the received light is a Gaussian spot or a Gaussian-like spot, the mode field distribution of the first grating layer (or grating coupler) matches the energy distribution of the spot of the received light, which can further improve the receiving efficiency of the first grating layer (or grating coupler).

[0036] In one possible design, the grating coupler further includes a second grating layer disposed above or below the first grating layer.

[0037] In this way, the receiving efficiency of the grating coupler can be further improved.

[0038] In a possible design, the grating coupler further includes a reflective layer disposed below the first grating layer, wherein the reflective layer is a distributed Bragg reflector (DBR) layer or a metal layer.

[0039] In this way, the receiving efficiency of the grating coupler can be further improved.

[0040] In a second aspect, a laser radar is provided, comprising a receiving component as described in the first aspect or any possible design of the first aspect.

[0041] Optionally, the lidar also includes a transmitting component.

[0042] Optionally, the transmitting component and the receiving component share a scanning device.

[0043] Optionally, the transmitting component includes a transmitting waveguide and a grating coupler, and the structural parameters of the grating layer in the grating coupler in the transmitting component correspond to the structural parameters of the grating layer in the grating coupler in the receiving component, wherein the structural parameters include one or more of shape, size, grating period, and duty cycle.

[0044] In a third aspect, a terminal is provided, comprising a receiving component as described in the first aspect or any possible design of the first aspect, or comprising a laser radar as described in the second aspect or any possible design of the second aspect.

[0045] The specific designs and beneficial effects of the second to third aspects mentioned above can refer to the corresponding designs and beneficial effects in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic diagram of the walk-off effect;

[0047] FIG2 is a schematic diagram of a laser radar with a single waveguide structure;

[0048] 3A and 3B are schematic diagrams of a laser radar with a multi-waveguide structure;

[0049] FIG4 is a schematic structural diagram of a receiving component provided in an embodiment of the present application;

[0050] FIG5 is a schematic structural diagram of a first grating layer 221 of a grating coupler 22 provided in an embodiment of the present application;

[0051] 6A to 6F are schematic diagrams of the mode field of the grating coupler 22 (or the first grating layer 221 ) provided in an embodiment of the present application;

[0052] FIG6G is a schematic structural diagram of the first grating layer 221 of the grating coupler 22 provided in an embodiment of the present application;

[0053] 7A to 7C are schematic structural diagrams of a grating coupler 22 provided in an embodiment of the present application;

[0054] 8A to 8D are schematic diagrams of a scanning device 01 of a grating coupler 22 provided in an embodiment of the present application;

[0055] FIG9 is a schematic diagram of the structure of a laser radar provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] The technical solutions provided in the embodiments of the present application can be applied to devices with laser detection capabilities, such as laser radars, or terminal devices with laser detection capabilities. Among them, the terminal device can be an intelligent device with laser detection capabilities, including but not limited to: smart home devices, such as TVs, sweeping robots, smart desk lamps, audio systems, smart lighting systems, appliance control systems, home background music, home theater systems, intercom systems, video surveillance, etc.; intelligent transportation equipment, such as cars, ships, drones, trains, vans, trucks, etc.; intelligent manufacturing equipment, such as robots, industrial equipment, intelligent logistics, smart factories, etc. Alternatively, the terminal device can also be a computer device with laser detection capabilities, such as a desktop computer, a personal computer, a server, etc. It should also be understood that the terminal device can also be a portable electronic device with laser detection capabilities, such as a mobile phone, a tablet computer, a PDA, headphones, speakers, wearable devices (such as smart watches), vehicle-mounted devices, virtual reality devices, augmented reality devices, etc. The following takes laser radar as an example.

[0057] LiDAR can be equipped with one or more rapidly rotating scanning devices to increase the detection frequency (the total number of detection points acquired by the LiDAR per second). Scanning devices such as rotating mirrors, microelectromechanical system (MEMS) galvanometers, and Galvo scanning galvanometers can be used. In a LiDAR with a scanning device, transmitted light is emitted by the scanning device, and received light is returned by the scanning device. Because the laser takes a certain amount of time to be emitted, hit the target, and then reflect from the target to the receiver, and during this time the scanning device has rotated a certain angle, a certain deflection angle will occur between the transmitted and received light.

[0058] As shown in Figure 1, (A) in Figure 1 illustrates the situation when the transmitted light is emitted through the scanning device, (B) in Figure 1 illustrates the situation when the receiving light is received by the laser radar via the scanning device when the scanning device is not rotating, and (C) and (D) in Figure 1 illustrate the situation when the receiving light is received by the laser radar via the scanning device when the scanning device is rotating. It can be understood that the optical path of the transmitted light and the optical path of the received light can be coaxial or non-coaxial. When the optical path of the transmitted light and the optical path of the received light are coaxial, the transmitter and the receiver can be integrated into one device. When the optical path of the transmitted light and the optical path of the received light are non-coaxial, the transmitter and the receiver can be implemented by two devices respectively, and the embodiments of the present application do not impose any restrictions.

[0059] As shown in Figure 1, when the scanning device rotates, the position of the receiving focal point on the receiving surface after focusing the received light deviates from the ideal receiving position (i.e., the position received by the receiver), resulting in reduced reception efficiency. This phenomenon of deflection angles between the transmitted and received light caused by the scanning device's rotation is called the transmit-receive asynchrony effect, also known as the walk-off effect, the descan effect, or other names.

[0060] For pulse time-of-flight (TOF) lidar, its receiver is generally an avalanche photodiode (APD), a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), etc. These devices have a large photosensitive surface (on the order of 100um). Therefore, although there is a problem of received light position offset caused by the walk-off effect, the received light after offset is still within the range of the receiver's receiving surface, which basically does not affect the ToF lidar receiving efficiency.

[0061] However, for waveguide-based lidars, such as frequency-modulated continuous waveform (FMCW) lidars, as shown in Figure 2, the receiver is an edge coupler (EC) + receiving waveguide structure (the waveguide used to receive light is called the receiving waveguide). The EC couples the received light into the receiving waveguide. This EC + receiving waveguide receiver has a limited receiving surface size (on the order of micrometers), and the receiving efficiency is sensitive to the position of the focused spot of the received light. Therefore, the walk-off effect, which causes positional shifts in the received light, can lead to a decrease in receiving efficiency. Furthermore, the farther the target distance and the greater the angular velocity of the scanning device, the more pronounced the walk-off effect, and the greater the drop in lidar receiving efficiency. It should be understood that Figure 2 only illustrates one receiving channel; in actual applications, multiple receiving channels are possible. Figure 2 primarily illustrates that the walk-off effect can cause the received light to shift in position, preventing the received light from accurately entering the receiving channel. The transmission directions of the transmitted and received light are simplified; in practice, these directions can vary.

[0062] One solution to mitigate the walk-off effect of FMCW lidar is to increase the number of waveguides in each receiving channel, as shown in Figures 3A and 3B. This creates a waveguide array to increase the equivalent receiving surface of the entire receiver, allowing the lidar to still detect optical signals even after the received light undergoes a walk-off angle offset. Figure 3A illustrates multiple receiving waveguides in a receiving channel corresponding to multiple detectors, while Figure 3B illustrates multiple receiving waveguides combined into a single waveguide corresponding to a single detector. Of course, Figures 3A and 3B are merely examples of multi-waveguide solutions; other multi-waveguide implementations are possible.

[0063] However, the prerequisite for using this multi-waveguide receiving solution is that the offset direction generated by the walk-off effect is parallel to the direction of the multi-waveguide arrangement. If the walk-off offset direction of the lidar is not parallel to the direction of the multi-waveguide arrangement, an additional optical transposition system is required to convert the walk-off offset direction into a direction parallel to the direction of the multi-waveguide arrangement. This increases the complexity of the lidar device, increases the optical modulation time and cost, and reduces reliability. Secondly, in the multi-waveguide receiving solution, the number and cost of components such as mixers, photodetectors (PDs), trans-impedance amplifiers (TIAs), and analog-to-digital converters (ADCs) will also increase many times, increasing the number of components, complexity, volume, and cost. In addition, even if a multi-waveguide receiving solution is adopted, it can only improve a number of specific discrete walk-off offset angles, and the overall receiving efficiency of the lidar is still low. If N multi-waveguides are combined into a single waveguide for reception (as shown in FIG3B ), the combined output optical power is much smaller than the input optical power. For example, the combined output optical power is 1 / N of the input optical power, resulting in poor overall optical reception efficiency.

[0064] In order to solve one or more of the above problems, a technical solution is provided in the embodiment of the present application to improve (or solve) the problem of low receiving efficiency of the laser radar caused by the walk-off effect, while taking into account reducing hardware costs and product size.

[0065] Referring to Figure 4 , a schematic diagram of the structure of a receiving assembly is provided in an embodiment of the present application. This receiving assembly can be used in a laser radar. The receiving assembly includes a scanning device 01 and at least one receiving channel 02. Received light is reflected from the surface of the scanning device and enters receiving channel 02. It should be understood that Figure 4 only illustrates one receiving channel 02 and is not limited thereto.

[0066] As shown in FIG4 , each receiving channel 02 includes at least one receiving waveguide 21 and at least one grating coupler (GC) 22. The number of receiving waveguides 21 can be the same as the number of grating couplers 22. There is a one-to-one correspondence between receiving waveguides 21 and grating couplers 22. Each grating coupler 22 is used to couple received light reflected from the scanning device 01 into the receiving waveguide 21 corresponding to the grating coupler 22.

[0067] It can be understood that the received light can pass through the receiving optical system before reaching the grating coupler 22. For example, the grating coupler 22 can be specifically used to couple the received light reflected back by the scanning device 01 and passing through the receiving optical system into the receiving waveguide 21 corresponding to the grating coupler 22.

[0068] It can be understood that FIG4 only illustrates one receiving waveguide 21 and one grating coupler 22 , and the present invention is not limited thereto.

[0069] It is understood that the operating principle of the grating coupler 22 is primarily based on the diffraction effect of the grating on light. When incident light enters the grating coupler 22, due to the change in the grating refractive index of the grating coupler 22, diffraction occurs, forming light interference. Through this interference, the grating coupler 22 can couple part of the incident light into the receiving waveguide 21.

[0070] In an embodiment of the present application, the receiving component of the laser radar adopts a combination of a grating coupler 22 and a receiving waveguide 21, and the grating coupler 22 couples the received light into the receiving waveguide 21. Compared with the end coupler, in terms of manufacturing process, the physical size of the receiving surface of the grating coupler 22 can be increased along the offset direction of the walk-off effect. Then, by further designing the structure of the grating layer of the grating coupler 22, the mode field of the grating coupler 22 can be increased at least in the offset direction of the walk-off effect, so that the received light can be received by the grating coupler 22 and coupled into the receiving waveguide 21 even after being offset due to the walk-off effect, thereby improving (or solving) the problem of low receiving efficiency of the laser radar caused by the walk-off effect.

[0071] Moreover, in the embodiment of the present application, the number of waveguides can be reduced. For example, a receiving channel can have at least a combination of only one receiving waveguide 21 and one grating coupler 22, and there is no need to add an additional optical transposition system. Therefore, the receiving efficiency of the laser radar can be improved while reducing the hardware cost and product size of the laser radar.

[0072] In addition, the position of the grating coupler 22 is relatively flexible and can be located at any position in the laser radar chip, so it can minimize unnecessary waveguide crossing and reduce crosstalk between waveguides, thereby improving the overall receiving performance of the laser radar.

[0073] It can be understood that the received light described herein being "received" by the grating coupler 22 means that the received light is "effectively received" by the grating coupler 22, such as the received light is "received and coupled into the receiving waveguide 21" by the grating coupler 22, and can ultimately be received by the lidar detector. In some embodiments, "receiving" herein can also be described as "coupling", and the "receiving efficiency" herein can also be described as "coupling efficiency". For example, the receiving efficiency of the grating coupler 22 can also be referred to as the coupling efficiency of the grating coupler 22, which can be understood as the ratio of the light output (or received) by the grating coupler 22 to the light input to the grating coupler 22, and is used to describe the receiving effect (or coupling effect) of the grating coupler 22 on light.

[0074] It will be understood that the mode field of the grating coupler 22 described herein refers to the portion of the grating coupler 22 that is capable of receiving and transmitting light. Only received light incident on the mode field of the first grating layer 221 can be received by the first grating layer 221 and coupled to the receiving waveguide 21. In some embodiments, the mode field of the grating coupler 22 can also be referred to as the spatial mode field of the grating coupler 22, the mode spot of the grating coupler 22, or the receiving surface or photosensitive surface of the grating coupler 22.

[0075] In one possible design, as shown in FIG5 , the grating coupler 22 may include a first grating layer 221, which includes a plurality of grating units 2211 arranged along a first direction. The plurality of grating units 2211 form a grating structure of the grating coupler 22. When light is incident on the first grating layer 221 along a third direction, the first grating layer 221 may couple the light into the receiving waveguide 21 along the thickness direction of the first grating layer 221.

[0076] The grating elements 2211 include portions that transmit light and portions that do not. Figure 5 illustrates an example in which a protrusion is the transmissive portion, and a groove between two adjacent protrusions is the non-transmissive portion. As shown in Figure 5 , the protrusions and grooves on the first grating layer 221 alternate and repeat, with one protrusion and one adjacent groove (on either side) forming a grating period.

[0077] In some embodiments, each grating unit 2211 may include a protrusion and a groove adjacent to the protrusion (on either side), i.e., each grating unit 2211 may include one grating period (as shown in FIG5 ). In other embodiments, each grating unit 2211 may include multiple protrusions and a groove adjacent to each of the multiple protrusions, i.e., each grating unit 2211 may include multiple grating periods (not shown in FIG5 ). For ease of description, the following description uses one grating unit 2211 as an example of one grating period.

[0078] The duty cycle of each grating element 2211 in the plurality of grating elements 2211 is within a first range. The duty cycle refers to the ratio of the portion of the grating element 2211 through which light is transmitted to the total portion of the grating element 2211, such as the ratio of the protrusions in the grating element 2211 to the total portion of the grating element 2211. When the duty cycle of the grating element 2211 is within the first range, the grating element 2211 can receive and transmit light, or in other words, the coupling efficiency of the grating element 2211 exceeds a threshold value (e.g., exceeds 0).

[0079] It is understood that the grating elements 2211 with duty cycles within the first range constitute the mode field of the first grating layer 221, i.e., the portion of the first grating layer 221 that can receive and transmit light. Only received light incident on the mode field of the first grating layer 221 can be received and transmitted by the first grating layer 221 (e.g., coupled to the receiving waveguide 21). It is understood that the grating layer is primarily responsible for coupling light in the grating coupler 22. Therefore, in some cases, the mode field of the first grating layer 221 can be equivalent to the mode field of the grating coupler 22.

[0080] In one possible example, the first range is a range where the duty cycle is greater than 0% and less than 100%, which can be expressed as (0%, 100%). Of course, this is only an example and is not limited to this. For example, the first range can also be (1%, 99%) or (5%, 95%).

[0081] In some embodiments, the duty cycle of the grating unit 2211 is associated with the grating period of the grating unit 2211 . When the duty cycle of the grating unit 2211 is within a first range, the grating period of the grating unit 2211 is within a second range.

[0082] For example, the association relationship can be: eff -mλ / P=sinθ;

[0083] Where P is the grating period; neff is the effective refractive index of the grating, which is related to the duty cycle; λ is the wavelength of light; θ is the angle between the transmitting / receiving direction and the normal; and m is the order.

[0084] Therefore, the duty cycle of each grating unit 2211 in the plurality of grating units 2211 within the first range can also be alternatively described as: the grating period of each grating unit 2211 in the plurality of grating units 2211 is within the second range; or, the duty cycle of each grating unit 2211 in the plurality of grating units 2211 is within the first range and the grating period of each grating unit 2211 in the plurality of grating units 2211 is within the second range.

[0085] It is understood that the duty cycle (or grating period) of the grating units 2211 at different positions in the first grating layer 221 can be the same or can vary (i.e., different), and this is not limited in the present embodiment. When the duty cycle of the grating units 2211 at different positions in the first grating layer 221 varies, the variation can be regular or irregular. For example, FIG5 shows an example where the duty cycle of the grating units 2211 increases along the thickness direction of the first grating layer 221, where the duty cycle of the grating units 2211 closest to the receiving waveguide 21 is the largest, and the duty cycle of the grating units 2211 farthest from the receiving waveguide 21 is the smallest. In practical applications, the design of the duty cycle (or grating period) of the grating units 2211 in the first grating layer 221 is not limited to the design shown in FIG5 . For example, the duty cycle of the grating unit 2211 closest to the receiving waveguide 21 may be the smallest, and the duty cycle of the grating unit 2211 farthest from the receiving waveguide 21 may be the largest.

[0086] The total length of the plurality of grating units 2211 in the first direction is greater than the first length. The first direction corresponds to the offset direction of the walk-off effect generated by the scanning device 01, or the first direction corresponds to the scanning direction generated by the scanning device 01.

[0087] As an example, the first direction is the offset direction of the walk-off effect generated by the scanning device 01, the first direction is parallel to the offset direction of the walk-off effect generated by the scanning device 01, or the first direction is approximately parallel to the offset direction of the walk-off effect generated by the scanning device 01 (for example, the angle between the first direction and the offset direction is less than a preset value), etc. It will be understood that the offset direction in FIG5 is based on the direction from the receiving waveguide 21 to the grating unit 2211 as an example, but is not limited to this. For example, it can also be the direction from the grating unit 2211 to the receiving waveguide 21 or other directions. FIG5 uses the first direction parallel to the offset direction of the walk-off effect generated by the scanning device 01 as an example, but is not limited to this.

[0088] It can be understood that the walk-off effect is caused by the rotation of the scanning device 01, so the deflection direction of the walk-off effect corresponds to the scanning direction of the scanning device 01. For example, the deflection direction of the walk-off effect is parallel to the scanning direction of the scanning device 01. Of course, the correspondence between the deflection direction of the walk-off effect and the scanning direction of the scanning device 01 can also be other relationships. For example, when an optical transposition system is used to transform the walk-off deflection direction into a direction perpendicular to the scanning direction of the scanning device 01, the deflection direction of the walk-off effect is perpendicular to the scanning direction of the scanning device 01. For ease of description, this article uses the example of the deflection direction of the walk-off effect being parallel to the scanning direction of the scanning device 01.

[0089] Since the total length of the multiple grating units 2211 in the first direction is greater than the first length, and the duty cycle of each grating unit 2211 in the multiple grating units 2211 is within the first range, and the grating units 2211 with a duty cycle within the first range constitute the mode field of the first grating layer 221 (or the grating coupler 22), the length of the mode field of the first grating layer 221 (or the grating coupler 22) in the first direction is greater than the first length.

[0090] In some embodiments, the first length may be related to a maximum offset corresponding to a walk-off effect generated by the scanning device 01. The offset corresponding to the walk-off effect refers to an offset in the receiving position of the received light in the mode field of the first grating layer 221 (or the grating coupler 22). For example, the first length is a+b, where a represents the length of the spatial mode field of the received light (i.e., the spatial region where the received light resides, also referred to as the mode field, light mode spot, or light spot of the received light) in the first direction, and b represents the maximum offset corresponding to the walk-off effect.

[0091] Through the above design, it can be achieved that the length of the mode field of the grating coupler 22 in the offset direction of the walk-off effect generated by the scanning device 01 is greater than the first length, so that the received light can still be located in the mode field of the grating coupler 22 after being offset due to the walk-off effect, thereby improving the receiving efficiency of the receiving component.

[0092] In one possible design, the total length of the plurality of grating elements 2211 in the first direction is greater than the first length, and the total length of the plurality of grating elements 2211 in the second direction is less than the first length, and the second direction is different from the first direction, for example, the second direction is perpendicular to the first direction. Alternatively, the length of the mode field of the grating coupler 22 in the second direction is less than the first length.

[0093] As an example, as shown in Figure 6A, which is a top view of the first grating layer 221, Figure 6A illustrates the shape of the mode field of the first grating layer 221 (or the grating coupler 22) when the total length of multiple grating units 2211 in the second direction is less than the first length. In this example, the shape of the mode field of the first grating layer 221 (or the grating coupler 22) is elliptical, wherein the long axis direction of the mode field is the first direction, and the short axis direction of the mode field is the second direction.

[0094] It can be understood that the elliptical mode field shown in Figure 6A is only an example. In actual situations, the mode field of the first grating layer 221 (or the grating coupler 22) can also be rectangular, trapezoidal or other irregular shapes, which is not limited in the embodiments of the present application.

[0095] In this way, the mode field of the first grating layer 221 (or the grating coupler 22) can be increased in the offset direction of the walk-off effect, while it does not need to be increased in the second direction, thereby improving the receiving efficiency of the first grating layer 221 (or the grating coupler 22) while reducing the size of the grating coupler 22 as much as possible.

[0096] Optionally, the size of the mode field of the first grating layer 221 (or the grating coupler 22) in the second direction can match the spatial mode field of the received light in the second direction. In this way, the receiving efficiency of the first grating layer 221 (or the grating coupler 22) can be further improved.

[0097] In another possible design, the total length of the plurality of grating elements 2211 in the first direction is greater than the first length, and the total length of the plurality of grating elements 2211 in the second direction is equal to (or approximately equal to) the total length of the plurality of grating elements 2211 in the first direction, and the second direction is perpendicular to the first direction. Alternatively, the length of the mode field of the grating coupler 22 in the second direction is equal to (or approximately equal to) the length of the mode field of the grating coupler 22 in the first direction.

[0098] As an example, as shown in Figure 6B, the shape of the mode field of the first grating layer 221 (or the grating coupler 22) is illustrated when the total length of multiple grating units 2211 in the second direction is equal to the first length. In this example, the shape of the mode field is circular.

[0099] It can be understood that the circular mode field shown in FIG6B is only an example. In actual situations, the mode field of the first grating layer 221 (or the grating coupler 22) can also be a square, diamond or other shape, which is not limited in the embodiment of the present application.

[0100] In this way, the mode field of the first grating layer 221 (or the grating coupler 22) can be increased in multiple directions (including the offset direction of the walk-off effect), further improving the receiving efficiency of the first grating layer 221 (or the grating coupler 22).

[0101] In one possible design, a first grating element 2211 among the plurality of grating elements 2211 is offset relative to the center of the plurality of grating elements 2211, and the offset direction of the first grating element 2211 relative to the center is the same as the offset direction of the walk-off effect generated by the scanning device 01. In other words, the first grating element 2211 is offset along a first direction relative to the center of the plurality of grating elements 2211.

[0102] The receiving efficiency (or coupling efficiency) of the first grating unit 2211 is the maximum value among the receiving efficiencies of each grating unit 2211 in the plurality of grating units 2211. For example, when the duty cycle of the first grating unit 2211 is a first value and / or the grating period of the first grating unit 2211 is a second value, the receiving efficiency of the first grating unit 2211 is the maximum value among the receiving efficiencies of each grating unit 2211 in the plurality of grating units 2211. The first value and / or the second value need to be determined based on actual conditions. For example, the first value may be 50% (i.e., the receiving efficiency is highest when the duty cycle is 50%), and this application does not impose any limitation thereto.

[0103] In this way, the mode field of the first grating layer 221 (or the grating coupler 22) can be a mode field with a peak value biased to one side, which can improve the reception efficiency of the first grating layer 221 (or the grating coupler 22) for the received light after the offset. For example, Figure 6C shows a case where the mode field of the first grating layer 221 (or the grating coupler 22) has a peak value biased to one side. The reception efficiency of the received light after the offset is higher than the reception efficiency of the received light before the offset (or without offset). It can be understood that Figure 6C takes an elliptical mode field as an example. In actual situations, the mode field of the first grating layer 221 (or the grating coupler 22) can also be rectangular, square, circular, diamond or other shapes, and the embodiments of the present application are not limited thereto. Figure 6C takes the example of the area of ​​the peak region being smaller than the light mode spot area of ​​the received light as an example, but is not limited thereto.

[0104] Optionally, the offset of the first grating unit 2211 relative to the center is related to the maximum offset corresponding to the walk-off effect generated by the scanning device 01. For example, the offset of the first grating unit 2211 relative to the center is equal to the maximum offset corresponding to the walk-off effect generated by the scanning device 01. In this way, when the walk-off effect is most severe (i.e., when the offset corresponding to the walk-off effect is maximum), the position of the received light is exactly at the peak position, and the first grating layer 221 (or the grating coupler 22) has the highest reception efficiency for the received light.

[0105] In one possible design, a first grating element 2211 among the plurality of grating elements 2211 is located at the center of the plurality of grating elements 2211; wherein the duty cycle of the first grating element 2211 is a first value, and the grating period of the first grating element 2211 is a second value. The receiving efficiency (or coupling efficiency) of the first grating element 2211 is the maximum value among the receiving efficiencies of the individual grating elements 2211 among the plurality of grating elements 2211. For example, when the duty cycle of the first grating element 2211 is the first value and / or the grating period of the first grating element 2211 is the second value, the receiving efficiency of the first grating element 2211 is the maximum value among the receiving efficiencies of the individual grating elements 2211 among the plurality of grating elements 2211.

[0106] In this way, the mode field of the first grating layer 221 (or the grating coupler 22) can be a mode field with a peak at the center, and the receiving efficiency of the position of the received light before the offset is higher. For example, as shown in Figure 6D, it illustrates the situation where the mode field of the first grating layer 221 (or the grating coupler 22) has a peak (receiving efficiency) located at the center of the mode field. The received light before the offset is just at the peak position, and the receiving efficiency is the highest. It can be understood that Figure 6D takes an elliptical mode field as an example. In actual situations, the mode field of the first grating layer 221 (or the grating coupler 22) can also be rectangular, square, circular, diamond or other shapes, and the embodiments of the present application are not limited thereto. Figure 6D takes the example of the area of ​​the peak region being smaller than the light mode spot area of ​​the received light as an example, and is not limited thereto.

[0107] In another possible design, the mode field of the first grating layer 221 (or the grating coupler 22) can also be designed as a Gaussian spot mode field or a quasi-Gaussian spot mode field, that is, the receiving efficiency of the mode field decreases from the peak position in the mode field to the surrounding areas.

[0108] For example, in the first direction, the reception efficiency of the mode field can be set to decrease sequentially along the first direction and the reverse direction of the first direction, starting from the peak position in the mode field. For example, the reception efficiency (or coupling efficiency) of each grating element 2211 in the plurality of grating elements 2211 decreases sequentially from the first grating element 2211 to the second grating element 2211, where the second grating element 2211 is the first grating element 2211 and / or the last grating element 2211 in the plurality of grating elements 2211 in the first direction. In a specific implementation, for example, the duty cycle of each grating element 2211 in the plurality of grating elements 2211 can be set to increase or decrease sequentially from the first grating element 2211 to the second grating element 2211.

[0109] For example, in the second direction, the reception efficiency of the mode field can be set to decrease sequentially along the second direction and the direction opposite to the second direction, starting from the peak position in the mode field. For example, the refractive index of each grating unit 2211 in the plurality of grating units 2211 can be set to decrease sequentially along the second direction and the direction opposite to the second direction. For example, in a specific implementation, the grating units 2211 at different positions in the second direction use materials or structures with different refractive indices.

[0110] As an example, FIG6E illustrates a Gaussian-like spot mode field with a peak offset to one side. As another example, FIG6F illustrates a Gaussian-like spot mode field with a peak located at the center. It will be appreciated that FIG6E and FIG6F illustrate elliptical mode fields as examples. In practice, the mode field of the first grating layer 221 (or grating coupler 22) may also be rectangular, square, circular, diamond, or other shapes, and this is not a limitation in the present embodiment.

[0111] Through the above design, when the spot of the received light is a Gaussian spot or a quasi-Gaussian spot, the mode field distribution of the first grating layer 221 (or the grating coupler 22) matches the energy distribution of the spot of the received light, which can further improve the receiving efficiency of the first grating layer 221 (or the grating coupler 22).

[0112] It can be understood that in the examples given in FIG. 6A to FIG. 6F , the optical pattern spots of the received light are all in the shape of a circle, but are not limited thereto and may be any other shape.

[0113] It will be appreciated that in the examples of Figures 5, 6A to 6F, etc., the gratings of the grating coupler 22 (or first grating layer 221) are all straight gratings, for example, the protrusions and grooves are all straight strips (or rectangular). In actual practice, the gratings are not limited to straight gratings, and can also be curved gratings. As shown in Figure 6G, the protrusions and grooves are curved strips. In addition, the dimensions of different grating units 2211 in the second direction can be the same or different, and this embodiment of the present application does not limit this.

[0114] In one possible design, the grating coupler 22 may be a multi-layer structure.

[0115] As an example, referring to FIG7A , the grating coupler 22 further includes a reflective layer 222. The first grating layer 221 and the reflective layer 222 are sequentially stacked along a third direction, where the third direction is the incident direction of the received light on the grating coupler 22. The reflective layer 222 is configured to reflect light transmitted from the first grating layer 221 to the reflective layer 222, thereby improving the coupling efficiency of the first grating layer 221.

[0116] In a specific implementation, the reflective layer 222 may be a distributed Bragg reflector (DBR) layer or a metal layer, etc., without limitation.

[0117] In this example, the receiving efficiency of the grating coupler 22 can be further improved by providing a reflective layer 222 under the first grating layer 221 .

[0118] As an example, referring to FIG7B , the grating coupler 22 further includes a second grating layer 223. FIG7B illustrates an example in which the second grating layer 223 is disposed above the first grating layer 221. However, the present invention is not limited thereto and the second grating layer 223 may also be disposed below the first grating layer 221. The structure of the second grating layer 223 may be the same as or different from that of the first grating layer 221, and this is not a limitation of the present embodiment. In this case, the mode field of the grating coupler 22 is the combination of the mode field of the first grating layer 221 and the mode field of the second grating layer 223.

[0119] It will be appreciated that FIG7B uses two grating layers as an example. In practice, the grating coupler 22 may also include more grating layers, and this is not a limitation in the present embodiment. Furthermore, FIG7B exaggerates the distance between the first grating layer 221 and the second grating layer 223 to clearly illustrate the spatial relationship between them. In practice, the distance between the first grating layer 221 and the second grating layer 223 may be smaller, for example, they may be positioned close together.

[0120] This example can further improve the receiving efficiency of the grating coupler 22 by setting a multi-layer grating.

[0121] As an example, the grating coupler 22 may further include a buried oxide (BOX) layer 224 and a substrate 225. FIG. 7C illustrates a possible structure of the grating coupler 22, comprising a first grating layer 221, a BOX layer, a reflective layer, and a substrate stacked sequentially along a third direction. The substrate 225 may support other layers in the grating coupler 22 (e.g., the first grating layer 221, the BOX layer, and the reflective layer). The BOX layer 224 is used to separate the substrate layer 225 from other layers to prevent light from other layers from leaking into the substrate layer 225. In some embodiments, the substrate layer 225 may be a silicon substrate.

[0122] It can be understood that FIG. 7A and FIG. 7B are merely some examples of the layer structure of the grating coupler 22 , and the actual layer structure of the grating coupler 22 is not limited thereto.

[0123] In one possible design, the scanning device 01 can be a one-dimensional (1D) scanning device, and the offset direction (or first direction) of the walk-off effect generated by the scanning device 01 corresponds to the scanning direction of the scanning device 01. For example, as shown in Figures 8A and 8B, the scanning device 01 shown in Figure 8A is a 1D galvanometer, and the scanning device 01 shown in Figure 8B is a 1D rotating mirror. It can be understood that the scanning device 01 in Figure 8A is a 1D galvanometer, and its scanning method is back-and-forth swinging, so the scanning direction can have two directions, and correspondingly, the offset direction can correspond to either of the two scanning directions, or both scanning directions simultaneously; the scanning device 01 in Figure 8B is a 1D rotating mirror, and its scanning method is 360° rotation and swinging, so the scanning direction can have only one direction, and correspondingly, the offset direction also has only one direction. Of course, in actual applications, in addition to 1D galvanometers and 1D rotating mirrors, the scanning device 01 can also be other implementations such as MEMS galvanometers and Galvo scanning galvanometers, without limitation.

[0124] In another possible design, scanning device 01 is a two-dimensional (2D) scanning device, and the offset direction (or first direction) of the walk-off effect generated by scanning device 01 corresponds to the scanning direction of the fast axis of 2D scanning device 01. For example, as shown in Figures 8C and 8D, the scanning device 01 in Figure 8C is an example of a 2D galvanometer, while the scanning device 01 in Figure 8D is an example of a 1D rotating mirror + 1D galvanometer. Of course, in actual applications, 2D scanning device 01 can also be implemented in other ways, without limitation.

[0125] Based on the same technical concept, an embodiment of the present application also provides a laser radar, which includes the receiving component mentioned above and also includes a transmitting component. The transmitting component and the receiving component share a scanning device 01.

[0126] In one possible design, as shown in FIG9 , the transmitting assembly may include a transmitting waveguide 31 and a grating coupler 32. The structural parameters of the grating layer in the grating coupler 32 in the transmitting assembly correspond to (e.g., are identical to) the structural parameters of the grating layer in the grating coupler 22 in the receiving assembly. These structural parameters include, but are not limited to, one or more of the following: structure, shape, size, grating period, duty cycle, etc. This further improves the receiving efficiency of the lidar.

[0127] Based on the same technical concept, an embodiment of the present application also provides a terminal, which includes the receiving component or laser radar described above. The terminal includes but is not limited to: smart home devices, such as televisions, sweeping robots, smart desk lamps, audio systems, smart lighting systems, appliance control systems, home background music, home theater systems, intercom systems, video surveillance, etc.; smart transportation equipment, such as cars, ships, drones, trains, vans, trucks, etc.; smart manufacturing equipment, such as robots, industrial equipment, smart logistics, smart factories, etc. Alternatively, the terminal device can also be a computer device with laser detection capabilities, such as a desktop computer, a personal computer, a server, etc. It should also be understood that the terminal device can also be a portable electronic device with laser detection capabilities, such as a mobile phone, a tablet computer, a PDA, headphones, speakers, wearable devices (such as smart watches), vehicle-mounted devices, virtual reality devices, augmented reality devices, etc. The following takes laser radar as an example.

[0128] It can be understood that the multiple involved in the embodiments of the present application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. In addition, it should be understood that although the terms first, second, etc. may be used to describe each object in the embodiments of the present invention, these objects should not be limited to these terms. These terms are only used to distinguish each object from each other.

[0129] The terms "including" and "having" and any variations thereof mentioned in the description of the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0130] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0131] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0132] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

Claims

1. A receiving component, characterized in that, Applied to a lidar, the receiving component includes a scanning device and at least one receiving channel; Each of the at least one receiving channels includes at least one receiving waveguide and at least one grating coupler, and the receiving waveguides and the grating couplers are in one-to-one correspondence. Each of the at least one grating couplers is configured to couple the received light reflected back by the scanning device into the receiving waveguide corresponding to each grating coupler; Wherein, the grating coupler includes a first grating layer, the first grating layer includes a plurality of grating units arranged along a first direction, the duty cycle of each grating unit in the plurality of grating units is within a first range, the total length of the plurality of grating units in the first direction is greater than a first length, and the first direction corresponds to the scanning direction of the scanning device.

2. The receiving component according to claim 1, wherein The grating period of each grating unit in the plurality of grating units is within a second range.

3. The receiving component according to claim 1 or 2, characterized in that The length of the mode field of the grating coupler in the first direction is greater than the first length.

4. The receiving component according to any one of claims 1-3, characterized in that The first length is related to the maximum offset corresponding to the walk-off effect generated by the scanning device.

5. The receiving component according to any one of claims 1-4, wherein The scanning device is a two-dimensional scanning device, and the first direction corresponds to the scanning direction of the fast axis in the two-dimensional scanning device.

6. The receiving component according to any one of claims 1-5, characterized in that, The total length of the plurality of grating units in a second direction perpendicular to the first direction is less than the first length.

7. The receiving component according to claim 6, characterized in that The length of the mode field of the grating coupler in the second direction is less than the first length.

8. The receiving component according to any one of claims 1-5, characterized in that The total length of the plurality of grating units in a second direction perpendicular to the first direction is equal to the total length of the plurality of grating units in the first direction.

9. The receiving component according to claim 8, characterized in that, The length of the mode field of the grating coupler in the second direction is equal to the length of the mode field of the grating coupler in the first direction.

10. The receiving component according to any one of claims 1-9, characterized in that, The first grating unit among the plurality of grating units is offset relative to the center of the plurality of grating units, and the offset direction of the first grating unit relative to the center is the same as the offset direction of the walk-off effect generated by the scanning device; Wherein, the duty cycle of the first grating unit is a first value, and the grating period of the first grating unit is a second value.

11. The receiving component according to claim 10, wherein The offset amount of the first grating unit relative to the center is related to the maximum offset corresponding to the walk-off effect generated by the scanning device.

12. The receiving component according to any one of claims 1-9, characterized in that, The first grating unit among the plurality of grating units is located at the center of the plurality of grating units; wherein, the duty cycle of the first grating unit is a first value, and the grating period of the first grating unit is a second value.

13. The receiving component according to any one of claims 10-12, characterized in that, The coupling efficiency of the first grating unit is the maximum value among the coupling efficiencies of each grating unit in the plurality of grating units.

14. The receiving component according to any one of claims 10-13, wherein The duty cycle of each grating unit in the plurality of grating units increases or decreases sequentially along the direction from the first grating unit to the second grating unit; or, the coupling efficiency of each grating unit in the plurality of grating units decreases sequentially along the direction from the first grating unit to the second grating unit; Among them, the second grating unit is the first grating unit or the last grating unit of the multiple grating units in the first direction.

15. The receiving component according to any one of claims 1-14, characterized in that The grating coupler further includes a second grating layer disposed above or below the first grating layer.

16. The receiving component according to any one of claims 1 to 15, characterized in that The grating coupler further includes a reflective layer disposed below the first grating layer, where the reflective layer is a distributed Bragg reflector (DBR) layer or a metal layer.

17. A lidar, characterized in that, The lidar includes the receiving component according to any one of claims 1-16. The lidar further includes a transmitting component, and the transmitting component and the receiving component share the scanning device.

18. The lidar according to claim 17, wherein, The transmitting component includes a transmitting waveguide and a grating coupler. The structural parameters of the grating layer in the grating coupler of the transmitting component correspond to the structural parameters of the grating layer in the grating coupler of the receiving component, where the structural parameters include one or more of shape, size, grating period, and duty cycle.

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