Phased array laser radar chip and laser radar

Abstract

The invention is suitable for the technical field of laser radars, and provides a phased array laser radar chip and a laser radar. The phased array laser radar chip comprises an input coupler, a transmitting module and a receiving module. The input coupler is used for coupling a laser beam to a chip and providing the laser beam to the transmitting module; the emission module comprises at least one emission unit, and the emission unit is used for emitting the laser beam to the detection space; the receiving module comprises a plurality of receiving units, the receiving units are used for receiving echo signals in the detection space, and the receiving units correspond to different scanning ranges. According to the phased array laser radar chip and the laser radar provided by the invention, large-field-angle scanning can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of lidar, and particularly relates to a phased array lidar chip and a lidar. Background Art

[0002] Lidar has been widely used in aspects such as autonomous driving, 3D printing, virtual reality, augmented reality, and intelligent transportation. With the popularization of the application scope, new requirements have been put forward for the performance parameters of lidar. Currently, the rotating and mechanical components in mechanical and semi-solid state lidars have the defects of short service life, high cost, and large volume. In view of the above problems, a pure solid-state phased array radar chip based on an integrated optical chip has emerged. The pure solid-state phased array lidar chip can combine advanced optical and electronic technologies to provide a more advanced, more compact, and more reliable lidar solution, and is particularly suitable for autonomous driving, robotics, and other fields that require high-performance laser sensing.

[0003] Currently, the pure solid-state phased array lidar chip generally uses an electro-optic or thermo-optic phase shifter to achieve scanning in the first dimension and changes the wavelength to achieve scanning in the second dimension. Limited by the limited tuning range of the tunable light source, the scanning range in the second dimension is only about 20°, which cannot meet the requirements of the field of view angle for autonomous driving. Summary of the Invention

[0004] The purpose of the present invention is to provide a phased array lidar chip and a lidar, aiming to improve the technical problem that the scanning range of the phased array lidar chip in the prior art is relatively small and cannot meet the requirements of the field of view angle for autonomous driving.

[0005] The present invention is implemented as follows. In a first aspect, a phased array lidar chip is provided, including:

[0006] An input coupler for coupling a laser beam onto the chip and providing it to the transmitting module;

[0007] A transmitting module including at least one transmitting unit for emitting the laser beam into the detection space; and

[0008] A receiving module including a plurality of receiving units for receiving echo signals in the detection space, and each of the receiving units corresponds to a different scanning range.

[0009] In some embodiments, the phased array lidar chip further includes:

[0010] A first beam splitter for receiving the laser beam provided by the input coupler, splitting the laser beam into probe light and reference light, and providing the probe light to the transmitting module to be emitted into the detection space through the transmitting module; and

[0011] A first beam combiner that receives the reference light and the echo signal, and the reference light and the echo signal are combined in the first beam combiner to generate a beat signal.

[0012] In some embodiments, the phased array lidar chip further includes a detection module, and the detection module is configured to receive the beat signal and convert the beat signal into a difference frequency electrical signal.

[0013] In some embodiments, the receiving units and the transmitting units are arranged in one-to-one correspondence, and the corresponding receiving units and transmitting units have the same scanning range to form a transceiver unit.

[0014] In some embodiments, the phased array lidar chip further includes a second beam splitter, and the second beam splitter is located between the input coupler and the transmitting module, and the second beam splitter is configured to divide the detection light into multiple beams and provide them to the multiple transmitting modules respectively.

[0015] In some embodiments, the phased array lidar chip further includes a plurality of first optical switches, and the first optical switches are located between the input coupler and the transmitting units, and the plurality of first optical switches are arranged in correspondence with the plurality of transmitting units, and the first optical switches are configured to control the conduction of the corresponding transmitting units.

[0016] In some embodiments, the phased array lidar chip further includes a plurality of second optical switches and a plurality of third optical switches. The second optical switches are located between the input coupler and the transmitting units, and the plurality of second optical switches are arranged in correspondence with the plurality of transmitting units, and the second optical switches are configured to control the conduction of the corresponding transmitting units. The plurality of third optical switches are arranged in correspondence with the plurality of receiving units, and the third optical switches are located between the receiving units and the detection module, and the third optical switches are configured to control the conduction of the corresponding receiving units.

[0017] In some embodiments, the transmitting unit includes a transmitting beam splitter, a first phase shifter group, and a first grating antenna connected in sequence; the laser beam can sequentially pass through the transmitting beam splitter, the first phase shifter group, and the first grating antenna and be emitted into the detection space;

[0018] The receiving unit includes a receiving beam combiner, a second phase shifter group, and a second grating antenna connected in sequence, and the echo signal can be received by sequentially passing through the second grating antenna, the second phase shifter group, and the receiving beam combiner.

[0019] In some embodiments, in at least one transceiver unit, the transmitting unit includes two of the transmitting beam splitters and two of the first phase shifter groups. In the same transmitting unit, the two transmitting beam splitters and the two first phase shifter groups are disposed on both sides of the same first grating antenna. The two transmitting beam splitters in the same first transmitting unit are provided to be connected to the input coupler through a first selection switch;

[0020] The receiving unit includes two of the receiving combiners and two of the second phase shifter groups. In the same receiving unit, the two receiving combiners and the two second phase shifter groups are disposed on both sides of the same second grating antenna. The two receiving combiners in the same second receiving unit are connected to the same detection module through a second selection switch.

[0021] In some embodiments, there is one transmitting unit, and the first grating antenna has multiple regions, and each region corresponds to a different scanning range.

[0022] In some embodiments, both the first grating antenna and the second grating antenna are any one of a sidewall-etched grating, a shallow-etched grating, a fully-etched grating, and a loaded grating.

[0023] In a second aspect, a lidar is provided, including a laser and the phased array lidar chip provided in each of the above embodiments, and the laser is used to provide a laser beam.

[0024] The technical effect of the first aspect of the present invention compared with the prior art is as follows: The phased array lidar chip provided in the embodiments of the present invention includes an input coupler, a transmitting module, and a receiving module, wherein the receiving module includes multiple receiving units, and each of the receiving units corresponds to a different scanning range. In this way, compared with the situation where each receiving unit corresponds to the same scanning range, the scanning range of the phased array lidar chip can be increased to a certain extent so that it can meet the requirements of the field of view angle for autonomous driving.

[0025] It can be understood that the beneficial effects of the above second aspect can refer to the relevant descriptions in the above first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention or the prior art. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1It is a schematic structural diagram of a lidar and a phased array lidar chip provided by an embodiment of the present invention;

[0028] Figure 2 It is a schematic structural diagram of a lidar and a phased array lidar chip provided by another embodiment of the present invention;

[0029] Figure 3 It is a schematic structural diagram of a lidar and a phased array lidar chip provided by another embodiment of the present invention;

[0030] Figure 4 It is a schematic structural diagram of a lidar and a phased array lidar chip provided by another embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the phase gradient change of the detection light after passing through the emission unit in the phased array lidar chip provided by the embodiment of the present invention;

[0032] Figure 6 It is a schematic diagram of the phase distribution of the detection light after passing through the emission unit in the phased array lidar chip provided by the embodiment of the present invention;

[0033] Figure 7 It is a schematic diagram of the output point cloud of the detection light after passing through the emission unit in the phased array lidar chip provided by the embodiment of the present invention;

[0034] Figure 8 It is a schematic structural diagram of the first grating antenna in the phased array lidar chip provided by the embodiment of the present invention;

[0035] Figure 9 It is a schematic structural diagram of a lidar and a phased array lidar chip provided by another embodiment of the present invention;

[0036] Figure 10 is Figure 9 a schematic diagram of the longitudinal field of view range corresponding to the shown phased array lidar chip;

[0037] Figure 11 It is a schematic structural diagram of a lidar and a phased array lidar chip provided by another embodiment of the present invention;

[0038] Figure 12 It is a schematic structural diagram of the first grating antenna in the phased array lidar chip.

[0039] Explanation of reference numerals:

[0040] 10. Substrate; 11. Optical isolation layer; 12. Waveguide layer; 13. First region; 14. Second region; 100. Laser; 200. Transceiver unit; 210. Transmitting unit; 211. Transmitting beam splitter; 212. First phase shifter group; 213. First grating antenna; 214. First selection switch; 220. Receiving unit; 221. Detection module; 222. Receiving beam combiner; 223. Second phase shifter group; 224. Second grating antenna; 226. Second selection switch; 300. Second beam splitter; 400. First optical switch; 500. Second optical switch; 600. Third optical switch; 700. First beam splitter; 800. First beam combiner. Detailed implementation manners

[0041] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0042] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0043] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0044] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0046] A lidar generally includes a laser and a phased array lidar chip. Among them, the laser is used to provide a laser beam, and the phased array lidar chip is used to receive and emit the laser beam. However, the current scanning range of the phased array lidar chip is small and cannot meet the requirements of the field of view angle for autonomous driving.

[0047] To improve the above problems, an embodiment of the present invention provides a phased array lidar chip. The phased array lidar chip includes an input coupler, a transmitting module, and a receiving module. The receiving module includes a plurality of receiving units, and each of the receiving units corresponds to a different scanning range. In this way, compared with the case where each receiving unit corresponds to the same scanning range, the scanning range of the phased array lidar chip can be increased to a certain extent so that it can meet the requirements of the field of view angle for autonomous driving.

[0048] Please refer to Figure 1 As shown, the phased array lidar chip includes an input coupler, a transmitting module, and a receiving module.

[0049] Among them, the input coupler is used to couple the laser beam onto the chip and provide it to the transmitting module. The transmitting module includes at least one transmitting unit 210, and the transmitting unit 210 is used to emit the laser beam into the detection space. The receiving module includes a plurality of receiving units 220. The receiving unit 220 is used to receive the echo signal in the detection space, and each receiving unit 220 corresponds to a different scanning range.

[0050] In this embodiment, one or more transmitting units 210 can be provided, which can be determined according to actual usage needs.

[0051] The working principle of the lidar using the phased array lidar chip provided by the embodiment of the present invention is as Figure 1 shown:

[0052] The laser 100 provides a laser beam, which serves as an input beam. The input beam is coupled onto the chip through the input coupler and enters the transmitting module. After being conducted by the transmitting unit 210 in the transmitting module, it is emitted into the detection space.

[0053] Then, the detection light in the detection space forms an echo signal after being reflected by an obstacle. The echo signal is received and processed by the receiving unit 220 in the receiving module, and then the processed signal is transmitted to the detection module 221 on or outside the chip, and then processed by an external data processing device to obtain relevant measurement data of the obstacles in the detection area, such as distance, obstacle volume, etc.

[0054] The phased array lidar chip provided by the embodiment of the present invention includes an input coupler, a transmitting module, and a receiving module. The receiving module includes a plurality of receiving units 220, and each receiving unit 220 corresponds to a different scanning range. In this way, compared with the situation where each receiving unit 220 corresponds to the same scanning range, the scanning range of the phased array lidar chip can be increased to a certain extent so that it can meet the field of view requirements for autonomous driving.

[0055] As Figure 1 shown, in some embodiments, the phased array lidar chip further includes a first beam splitter 700 and a first beam combiner 800. The first beam splitter 700 receives the laser beam provided by the input coupler, divides the laser beam into a detection light and a reference light, and provides the detection light to the transmitting module, which is emitted to the detection space through the transmitting module. The first beam combiner 800 receives the reference light and the echo signal. The reference light and the echo signal are combined in the first beam combiner 800 to generate a beat signal.

[0056] The first beam splitter 700 may have two light output ports, three light output ports, or more light output ports, which can be determined according to actual usage needs. The first beam combiner 800 may also have two light input ports, three light input ports, or more light input ports, which can be determined according to actual usage needs.

[0057] As Figure 1 、 Figure 2 、 Figure 3 shown, in some embodiments, there are multiple transmitting units 210 and multiple receiving units 220. At this time, a first beam splitter 700 can be provided between each transmitting unit 210 and the laser 100. Each first beam splitter 700 may have two light output ports. One light output port is used to output the detection light and is connected to the transmitting unit 210, and the other light output port is used to output the reference light; at the same time, a first beam combiner 800 can also be provided for each receiving unit 220. As Figure 4 shown, in some other embodiments, one first beam splitter 700 can be provided. The detection light can be divided into multiple beams through a beam splitting structure and provided to multiple transmitting units 210; one first beam combiner 800 can also be provided, and the echo signals transmitted by multiple receiving units 220 can be combined through this first beam combiner 800.

[0058] Adopting the solution provided by this embodiment can make the phased array lidar chip have higher integration and a more compact structure.

[0059] As Figure 1 shown, in some embodiments, the phased array lidar chip further includes a detection module 221. The detection module 221 is used to receive the beat signal and convert the beat signal into a difference frequency electrical signal.

[0060] The detection module 221 may include one or more detectors, and may also include other structures according to the usage requirements, which may be determined specifically according to the usage requirements.

[0061] Adopting the solution provided by this embodiment can make the phased array lidar chip have higher integration and more comprehensive functions.

[0062] Such as Figure 1 As shown, in some embodiments, the receiving unit 220 and the transmitting unit 210 are arranged in one-to-one correspondence, and the corresponding receiving unit 220 and transmitting unit 210 have the same scanning range, forming a transceiver unit 200.

[0063] In this embodiment, the number of the transmitting units 210 is the same as that of the receiving units 220, and they are arranged in one-to-one correspondence. The corresponding receiving unit 220 and transmitting unit 210 refer to the receiving unit 220 and transmitting unit 210 with the same scanning range.

[0064] In this embodiment, there are multiple groups of transceiver units 200 (TX / RX) on the phased array lidar chip, including but not limited to 2 - 20 groups of transceiver units 200. Among them, TX is the abbreviation of Transmit (send), representing the transmitting unit 210; RX is the abbreviation of Receive (receive), representing the receiving unit 220. The scanning ranges of different transceiver units 200 are different. Under the input light beam of the same wavelength, the wavelength emission angles of different transceiver units 200 are different, and the angular range of the second dimension is divided into multiple sub-regions. Then, by using a tunable light source (i.e., the laser 100) to move the wavelength of the incident light (laser beam), it is possible to cover each emission angle within each sub-region. Based on the above solution, it is possible to cover a wavelength scanning angle of 80° - 100° and a phase scanning angle of 120° on a single chip.

[0065] A single TX / RX unit can achieve a scanning range of 120° in the phase direction, and the change of the emission angle with the wavelength is generally 0.05° / nm - 0.16° / nm. A single TX / RX unit can generally achieve a scanning of about 16° in a wavelength range of nearly 100 nm. By splicing between different arrays, a longitudinal scanning range of 80° can be finally achieved.

[0066] Such as Figure 2 As shown, in some embodiments, the phased array lidar chip further includes a second beam splitter 300. The second beam splitter 300 is located between the input coupler and the transmitting module, and the second beam splitter 300 is used to divide the detection light into multiple beams and provide them to multiple transmitting modules respectively.

[0067] By adopting the solution provided in this embodiment, multiple transmitting units 210 can share one laser 100, reducing the number of lasers 100 and external circuit control units, and lowering the complexity of the system. As a result, the manufacturing cost of the lidar using the phased array lidar chip provided in this embodiment is relatively low, and the structure is compact.

[0068] As Figure 3 shown, in some embodiments, the phased array lidar chip further includes multiple first optical switches 400. The first optical switches 400 are located between the input coupler and the transmitting units 210. The multiple first optical switches 400 are correspondingly arranged with the multiple transmitting units 210. The first optical switch 400 is used to control the corresponding transmitting unit 210 to conduct.

[0069] For the solution provided in this embodiment, a single tunable laser 100 can be used for input, and the first optical switch 400 can be used to switch between different transceiver units 200. Each transceiver unit 200 respectively covers a certain range of longitudinal emission angle range, and the longitudinal emission angle ranges of multiple transceiver units 200 are spliced to achieve large-angle emission. Among them, the implementation methods of the first optical switch 400 include but are not limited to electro-optic switches, thermo-optic switches, wavelength selection switches, etc.

[0070] By adopting the solution provided in this embodiment, multiple transceiver units 200 can be made to conduct in a single path according to the usage needs. Furthermore, users can select a suitable detection range according to the detection needs, achieving precise control and reducing energy consumption.

[0071] As Figure 4 shown, in some embodiments, the phased array lidar chip further includes multiple second optical switches 500 and multiple third optical switches 600. The second optical switches 500 are located between the input coupler and the transmitting units 210. The multiple second optical switches 500 are correspondingly arranged with the multiple transmitting units 210. The second optical switch 500 is used to control the corresponding transmitting unit 210 to conduct. The multiple third optical switches 600 are correspondingly arranged with the multiple receiving units 220. The third optical switch 600 is located between the receiving unit 220 and the detection module 221. The third optical switch 600 is used to control the corresponding receiving unit 220 to conduct.

[0072] In order to reduce the number of receiving balanced detectors and backend circuits and lower the system complexity, the Figure 4 structure shown can be adopted. Each receiving antenna (i.e., the second grating antenna 224) is connected and gated by a 1xN third optical switch 600, which is synchronized in time with the 1xN second optical switch 500 in the transmitting unit 210 and has corresponding ports. Based on the above method, the complexity of the optical system can be reduced to a single tunable laser 100 and a pair of balanced detectors.

[0073] AsFigure 1 As shown, in some embodiments, the transmitting unit 210 includes a transmitting beam splitter 211, a first phase shifter group 212, and a first grating antenna 213 that are connected in sequence. The laser beam can pass through the transmitting beam splitter 211, the first phase shifter group 212, and the first grating antenna 213 in sequence and be emitted into the detection space.

[0074] Among them, the transmitting beam splitter 211 is used to receive the detection light and divide the detection light into multiple beams. The transmitting beam splitter 211 has multiple signal output terminals, and the first phase shifter group 212 has multiple first phase shifters. The multiple first phase shifters are correspondingly connected to the multiple signal output terminals. Each first phase shifter is used to correspondingly receive and conduct one of the divided beams, and is also used to change the emission angle range of the divided beam in the transverse direction. The first grating antenna 213 is used to receive, conduct, and output all the divided beams conducted by the first phase shifter group 212, combine all the divided beams, and is also used to change the emission angle range of the combined detection light in the longitudinal direction.

[0075] The receiving unit 220 includes a receiving combiner 222, a second phase shifter group 223, and a second grating antenna 224 that are connected in sequence. The echo signal can pass through the second grating antenna 224, the second phase shifter group 223, and the receiving combiner 222 in sequence and be received.

[0076] Among them, the second grating antenna 224 is used to receive and conduct the echo signal formed after the detection light is reflected by the detection space, and is also used to change the reception angle range of the echo signal in the longitudinal direction. The second phase shifter group 223 is used to receive and conduct the echo signal conducted by the second grating antenna 224, and is also used to change the reception angle range of the echo signal in the transverse direction. The second phase shifter group 223 has multiple second phase shifters. The receiving combiner 222 has multiple signal input terminals, and each signal input terminal is connected to a second phase shifter. The receiving combiner 222 is used to receive and combine the echo signals conducted by the second phase shifter group 223, and is also used to conduct the combined echo signal to the detection module 221. The detection module 221 is used to receive and process the echo signal.

[0077] In this embodiment, all the transmitting units 210 can emit detection light outward at multiple emission angle ranges. The effective refractive indices of the second grating antennas 224 in different receiving units 220 are different.

[0078] All the above-mentioned transmitting units 210 can emit detection light outward at multiple emission angle ranges. When there is one transmitting unit 210, it can be achieved by setting multiple regions with different effective refractive indices in the first grating antenna 213. When there are multiple transmitting units 210, it can be achieved by making the effective refractive indices of the first grating antennas 213 in different transmitting units 210 different, which can be specifically determined according to the usage requirements.

[0079] The difference in the effective refractive index can be achieved by changing the width, depth, etc. between adjacent grating bars in the first grating antenna 213 and the second grating antenna 224, and specifically can be determined according to the usage requirements.

[0080] Any two of the above multiple emission angle ranges may have an overlapping area or may not have an overlapping area. For example, one emission angle range may be 0° - 10°, another emission angle range may be 10° - 20°, or may be 5° - 20°, and specifically can be determined according to the usage requirements.

[0081] The working principle of the lidar using the phased array lidar chip provided by the embodiment of the present invention is as Figure 1 and Figure 5 shown as follows:

[0082] The laser 100 provides a laser beam, which is used as an input beam. After being coupled to the chip by the input coupler, it is then divided into a detection light and a reference light by the first beam splitter 700. The detection light enters the emission beam splitter 211 and is then guided into a plurality of waveguide channels. The number of waveguide channels includes but is not limited to any value from 128 to 8192. Then it is divided into a plurality of sub - beams. Each sub - beam enters a phase shifter in the first phase shifter group 212 and is respectively applied with different phases to form a phase gradient in one dimension (i.e., the x - direction phase gradient), that is, the emission angle range is changed in the transverse direction. Among them, the phase - shifting principle of the phase shifter includes but is not limited to the Pockels effect, the plasma dispersion effect, the thermo - optic effect, and the acousto - optic effect.

[0083] Then each sub - beam enters the area where the first grating antenna 213 is located, undergoes beam combination, and at the same time forms a phase gradient in the second dimension (i.e., the y - direction phase gradient) under the diffraction of the first grating antenna 213, that is, the emission angle range is changed in the longitudinal direction. Then it exits from the first grating antenna 213 into the detection space. The phase distribution of the detection light after exiting from the emission unit 210 is as Figure 6 shown, and the output point cloud is as Figure 7 shown.

[0084] Then the detection light entering the detection space is reflected by the obstacle to form an echo signal. The echo signal first passes through the second grating antenna 224 to change the longitudinal reception angle range, and then enters each phase shifter in the second phase shifter group 223. After the transverse reception angle range is changed by the phase shifters in the second phase shifter group 223, it is combined by the receiving beam combiner 222. At the same time, the reference light and the echo signal form a beat signal at the receiving beam combiner 222. Then the beat signal enters the detection module 221. The detection module 221 processes the beat signal and outputs the corresponding electrical signal, and then the relevant measurement data of the obstacle, such as distance, obstacle volume, etc., is obtained through the processing of the external data processing device.

[0085] In the above process, after passing through the transmitting unit 210, the phase plane arrays finally formed by the phase gradients in two dimensions are as shown in the figure. By adjusting the phase gradients of the phase shifters and the wavelength of the laser beam, spot scanning in two dimensions can be achieved.

[0086] In addition to the laser 100 and the transceiver unit 200, the phased array lidar chip generally further includes a substrate 10, where the transceiver unit 200 is disposed on the substrate 10, and the laser 100 is disposed outside the substrate 10. At this time, the installation method of the first grating antenna 213 can be as Figure 8 shown. An optical isolation layer 11 is disposed on the surface of the substrate 10, a waveguide layer 12 is disposed on the surface of the optical isolation layer 11, and the first grating antenna 213 is disposed on the waveguide layer 12.

[0087] The diffraction principle of the detection light when passing through the first grating antenna 213 is as follows:

[0088] The first grating antenna 213 is generally composed of a periodic grating structure, and a periodic refractive index distribution is formed by patterning the waveguide. When a light beam passes through the grating structure, the phenomenon of light diffraction will occur, and part of the light beam energy will be diffracted. The incident light wavelength and the periodic refractive index distribution determine the phase difference between adjacent diffraction units, that is, the exit angle in the second dimension. The exit angle of the diffraction grating can be described by the diffraction equation. The first-order diffraction equation can be expressed as:

[0089] neff j -n1·sin(0)=λ / Λ;

[0090] where Λ is the period of the grating, n1 is the refractive index of the cladding, λ is the wavelength of the incident light, θ is the angle between the diffracted light and the normal of the exit plane, and neff j is the equivalent refractive index of the waveguide in the grating region. As Figure 8 shown, the first grating antenna 213 has alternately distributed first regions 13 and second regions 14, where the effective refractive index of the first region 13 is neff1, the effective refractive index of the second region 14 is neff2, and the equivalent refractive index neff j of the first grating antenna 213 can be expressed as:

[0091] neff j =neff1·FF + neff2·(1 - FF).

[0092] where FF is the duty cycle of the grating. It can be seen from the formula that when the incident light wavelength λ or the equivalent refractive index neff j of the grating changes, the exit angle will change, thereby achieving beam scanning.

[0093] In this embodiment, the integrated optical technology on which the phased array lidar chip is based includes, but is not limited to, silicon on insulator, silicon nitride, and thin film lithium niobate.

[0094] The phased array lidar chip provided in the embodiment of the present application has a simple structure for the transmitting unit 210 and the receiving unit 220. At least one transmitting unit 210 and multiple receiving units 220 can form multiple transceiver phased arrays. By adjusting the antenna structures of different arrays, different emission angles can be achieved at the same wavelength. Finally, the point clouds of the transceiver units are stitched together to achieve large field of view scanning, thereby meeting the requirements for large field of view in two dimensions in scenarios such as autonomous driving. As Figure 9 shown, in some embodiments, in at least one transceiver unit, the transmitting unit 210 includes two transmitting beam splitters 211 and two first phase shifter groups 212. The two transmitting beam splitters 211 and the two first phase shifter groups 212 in the same transmitting unit 210 are disposed on both sides of the same first grating antenna 213. The two transmitting beam splitters 211 in the same first transmitting unit 210 are connected to the input coupler through a selection switch. The receiving unit 220 includes two receiving combiners 222 and two second phase shifter groups 223. The two receiving combiners 222 and the two second phase shifter groups 223 in the same receiving unit 220 are disposed on both sides of the same second grating antenna 224. The two receiving combiners 222 in the same second receiving unit 220 are connected to the same detection module 221 through a selection switch.

[0095] As Figure 10 shown, by adopting the structure provided in this embodiment, an 80° longitudinal field of view range can be achieved by using two sets of transceiver units. The implementation method is to place phase shifters and beam splitting structures on both sides of the antenna structure, and select the light to enter from the left or right side of the second grating antenna 224 through the first optical switch 400. Since the propagation direction of light is completely reversed, the emission angle in the far field will also be symmetric along the chip normal. Therefore, the field of view range of a single transceiver unit is doubled, and the required large field of view range is further stitched by two sets of transceiver units.

[0096] As Figure 11 shown, in some embodiments, there is one transmitting unit 210, and the first grating antenna 213 has multiple regions, and each region corresponds to a different scanning range.

[0097] In this embodiment, the first grating antenna 213 has multiple grating regions, and different regions have different effective refractive indices, which correspond one by one to the second grating antennas 224 in each receiving unit 220. This can reduce the number of transmitting units 210 in the chip, which is beneficial to the miniaturization design of the chip or arranging more receiving units 220 in a limited chip area.

[0098] As Figure 11As shown, in some embodiments, the laser 100 is provided with one, and the transmitting unit 210 is provided with one.

[0099] With the structure provided in this embodiment, the laser 100 can adopt a single-channel tunable laser. The first beam splitter 700 is used to split the light into a beam of detection gratings and multiple reference lights for receiving beat frequencies. The first grating antenna 213 has multiple grating regions, and different regions have different effective refractive indices, which correspond one-to-one with the second grating antennas 224 in each receiving unit 220. Based on a single-channel laser, this solution reduces the transmitting unit 210 to one, which can significantly reduce the chip area or arrange more receiving units 220 in a limited chip area.

[0100] In some embodiments, both the first grating antenna 213 and the second grating antenna 224 are any one of sidewall-etched gratings, shallow-etched gratings, fully-etched gratings, and loaded gratings.

[0101] As Figure 12 shown is a schematic structural diagram of the first grating antenna 213, and three possible antenna structural diagrams are given in the figure. The first one is as shown in (a) in Figure 12 , which is a sidewall-etched grating with periodically arranged waveguide structures of different widths. The second structure is as shown in (b) in Figure 12 , which is a shallow-etched grating with the same width of the grating structure but different thicknesses, resulting in a refractive index difference. The third structure is as shown in (c) in Figure 12 , which is a fully-etched grating with only cladding material in some regions within each period. The fourth structure is a loaded grating, which forms a periodic structure by depositing optical materials and patterning. The types of optical materials include, but are not limited to, amorphous silicon, polycrystalline silicon, silicon nitride, and silicon oxynitride.

[0102] The first grating antenna 213 and the second grating antenna 224 adopt the structure provided in this embodiment, which is convenient for design and fabrication and has mature technology.

[0103] As Figure 1 shown, another embodiment of the present invention also provides a lidar, including a laser 100 and the phased array lidar chip provided in each of the above embodiments. Among them, the laser 100 is used to provide a laser beam.

[0104] The laser 100 can be provided with one or more, which can be determined according to specific usage requirements.

[0105] Using the lidar provided in the embodiments of the present invention can, to a certain extent, increase the scanning range and meet the requirements of the field of view angle for autonomous driving.

[0106] The above description is only a preferred embodiment of the present invention, and only specifically describes the technical principle of the present invention. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanation here, any modification, equivalent substitution and improvement made within the spirit and principle of the present invention, and other specific embodiments of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A phased array lidar chip, characterized in that, Comprising: An input coupler for coupling a laser beam onto the chip and providing it to the transmitting module; A transmitting module including at least one transmitting unit for emitting the laser beam into the detection space; And A receiving module including a plurality of receiving units for receiving the echo signal in the detection space, and each of the receiving units corresponding to a different scanning range.

2. The phased array lidar chip according to claim 1, characterized in that, The phased array lidar chip further includes: A first beam splitter for receiving the laser beam provided by the input coupler, splitting the laser beam into a detection light and a reference light, and providing the detection light to the transmitting module to be emitted into the detection space through the transmitting module; and A first beam combiner for receiving the reference light and the echo signal, and combining the reference light and the echo signal in the first beam combiner to generate a beat frequency signal.

3. The phased array lidar chip according to claim 2, wherein, The phased array lidar chip further includes a detection module for receiving the beat frequency signal and converting the beat frequency signal into a difference frequency electrical signal.

4. The phased array lidar chip according to claim 2, wherein The receiving units and the transmitting units are arranged in one-to-one correspondence, and the corresponding receiving unit and transmitting unit have the same scanning interval to form a transceiver unit.

5. The phased array lidar chip according to claim 4, wherein The phased array lidar chip further includes a second beam splitter located between the input coupler and the transmitting module, and the second beam splitter is used for splitting the detection light into multiple beams and providing them to the multiple transmitting modules respectively.

6. The phased array lidar chip according to claim 4, wherein, The phased array lidar chip further includes a plurality of first optical switches located between the input coupler and the transmitting units, and the plurality of first optical switches are arranged in correspondence with the plurality of transmitting units, and the first optical switches are used for controlling the conduction of the corresponding transmitting units.

7. The phased array lidar chip according to claim 3, wherein, The phased array lidar chip further includes a plurality of second optical switches and a plurality of third optical switches. The second optical switches are located between the input coupler and the transmitting units, and the plurality of second optical switches are arranged in correspondence with the plurality of transmitting units. The second optical switches are used for controlling the conduction of the corresponding transmitting units. The plurality of third optical switches are arranged in correspondence with the plurality of receiving units. The third optical switches are located between the receiving units and the detection module, and the third optical switches are used for controlling the conduction of the corresponding receiving units.

8. The phased array lidar chip according to any one of claims 2-7, characterized in that The transmitting unit includes a transmitting beam splitter, a first phase shifter group, and a first grating antenna connected in sequence; the laser beam can be emitted into the detection space through the transmitting beam splitter, the first phase shifter group, and the first grating antenna in sequence; The receiving unit includes a receiving beam combiner, a second phase shifter group, and a second grating antenna connected in sequence, and the echo signal can be received through the second grating antenna, the second phase shifter group, and the receiving beam combiner in sequence.

9. The phased array lidar chip according to claim 8, wherein, In at least one transceiver unit, the transmitting unit includes two transmitting beam splitters and two first phase shifter groups. The two transmitting beam splitters and the two first phase shifter groups in the same transmitting unit are respectively arranged on both sides of the same first grating antenna, and the two transmitting beam splitters in the same transmitting unit are connected to the input coupler through a first selection switch; The receiving unit includes two of the receiving beam combiners and two of the second phase shifter groups. In the same receiving unit, the two receiving beam combiners and the two second phase shifter groups are disposed on both sides of the same second grating antenna. The two receiving beam combiners in the same receiving unit are connected to the same detection module through a second selection switch.

10. The phased array lidar chip according to claim 8, wherein, One transmitting unit is provided. The first grating antenna has multiple regions, and each region corresponds to a different scanning range.

11. The phased array lidar chip according to claim 8, wherein Both the first grating antenna and the second grating antenna are any one of a sidewall etched grating, a shallow etched grating, a fully etched grating, and a loaded grating.

12. A lidar, characterized in that, It includes a laser and the phased array lidar chip according to any one of claims 1-11. The laser is used to provide a laser beam.

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