Laser radar chip and detection equipment

Abstract

The invention provides a laser radar chip and detection equipment, and relates to the technical field of radars. The laser radar chip comprises a first optical coupler, an optical power distribution network, a plurality of phase shifters and a grating antenna array which are manufactured on a polarization insensitive platform, the first optical coupler is used for receiving an input optical signal, separating the input optical signal including a local oscillator optical signal and a polarized light signal, transmitting the polarized light signal obtained by separation to the optical power distribution network, and outputting the local oscillator optical signal; the optical power distribution network is used for transmitting the polarized light signal to the plurality of phase shifters; each phase shifter is used for performing phase shifting processing on the received polarized light signal; the grating antenna array is used for sending each polarized light signal after phase shift processing; the grating antenna array is further used for receiving feedback polarized light signals, the feedback polarized light signals are transmitted to the optical power distribution network through the multiple phase shifters, and the optical power distribution network is further used for outputting the feedback polarized light signals received by the grating antenna array.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar, in particular to a laser radar chip and a detection device. BACKGROUND

[0002] In a laser radar system, an optical phased array (OPA) does not contain mechanical moving parts, has the advantages of fast scanning speed, high reliability, and can realize full solid-state scanning and arbitrary position scanning. The optical phased array based on a silicon photonics integrated chip is compatible with mature complementary metal oxide semiconductor (CMOS) technology, and can realize large-scale production and commercial application of laser radar at a lower cost.

[0003] In the existing on-chip optical phased array system, the transmitting scanning array is composed of several grating antennas. For the grating antennas designed based on existing platforms such as SiN (‌Silicon Nitride‌), 220 nm SOI (‌Silicon-on-Insulator‌), and LNOI (Lithium Niobate on Insulator), there is a large difference in the transmission angle for TM (parallel polarization wave) and TE (vertical polarization wave). In the case of simultaneous input of TE and TM, the transmission angle difference of the beams corresponding to the two polarization states is greater than 30°, and it is impossible to use signals of the two polarization states to detect the same target at the same time. SUMMARY

[0004] The present application provides a laser radar chip and a detection device to realize the use of signals of two polarization states to detect the same target at the same time, and achieve the purpose of obtaining polarization information.

[0005] In a first aspect, the present application provides a laser radar chip, comprising: a first optical coupler, an optical power distribution network, a plurality of phase shifters, and a grating antenna array, which are manufactured on a polarization-insensitive platform; the first optical coupler is used to receive an input optical signal, separate the input optical signal into a local oscillator optical signal and a polarized optical signal, transmit the separated polarized optical signal to the optical power distribution network, and output the local oscillator optical signal; the polarized optical signal includes a vertical polarization wave and a parallel polarization wave; the optical power distribution network is used to transmit the polarized optical signal to the plurality of phase shifters; each phase shifter is used to perform phase shift processing on the received polarized optical signal; the grating antenna array is used to transmit each phase-shifted polarized optical signal; the grating antenna array is also used to receive a feedback polarized optical signal, the feedback polarized optical signal is transmitted to the optical power distribution network through the plurality of phase shifters, and the optical power distribution network is also used to output the feedback polarized optical signal received by the grating antenna array.

[0006] In this embodiment, by fabricating a first optical coupler, an optical power distribution network, multiple phase shifters, and a grating antenna array on a polarization-insensitive platform, the difference between the emission angles of the emitted vertically polarized wave and the parallelly polarized wave is small due to its polarization-insensitive characteristic. This satisfies the resolution requirements for object detection in applications such as industrial inspection and blind spot radar. Therefore, these two polarized light signals can be considered as detecting the same target.

[0007] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the lidar chip further includes: a second optical coupler fabricated on the polarization-insensitive platform; the second optical coupler is used to receive the input optical signal, split the received input optical signal into a first input optical signal and a second input optical signal according to a preset ratio, transmit the first input optical signal to the first optical coupler, and output the second input optical signal, wherein the second input optical signal is used to detect whether the polarization signal in the input optical signal is balanced.

[0008] In this embodiment, the input optical signal is split by a second optical coupler. The split first input optical signal is sent to the first optical coupler for subsequent transmission of polarization information. The second input optical signal is output as a detection criterion for whether the polarized optical signal is balanced, facilitating adjustment of the input optical signal based on the second input optical signal.

[0009] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the lidar chip further includes: a balance detection module manufactured on the polarization-insensitive platform; the balance detection module is used to receive the second input optical signal output by the second optical coupler, and detect the intensity of the second vertically polarized wave and the second parallelly polarized wave included in the polarized optical signal in the second input optical signal, to obtain a first signal characterizing the intensity of the second vertically polarized wave and a second signal characterizing the intensity of the second parallelly polarized wave.

[0010] In this embodiment, a balance detection module receives the second input optical signal and splits it into a first signal characterizing the intensity of the second vertically polarized wave and a second signal characterizing the intensity of the second parallelly polarized wave, thereby detecting the intensity of the polarized light signal. This allows for adjustment of the ratio of vertically polarized waves to parallelly polarized waves in the input optical signal based on the first and second signals.

[0011] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the balance detection module includes: a first polarization beam splitter, a first photodetector, and a second photodetector; the first polarization beam splitter is used to receive the second input optical signal output from the second output terminal of the second optical coupler, and separate the polarized light signal in the second input optical signal, including a second vertically polarized wave and a second parallelly polarized wave, and transmit the separated second vertically polarized wave to the first photodetector, and transmit the separated second parallelly polarized wave to the second photodetector; the first photodetector is used to detect the intensity of the second vertically polarized wave and output the first signal; the second photodetector is used to detect the intensity of the second parallelly polarized wave and output the second signal.

[0012] In this embodiment, a first polarization beam splitter is used to separate the two polarized light signals, and then two photodetectors are used to detect the intensity of one polarized light signal respectively. This allows for simple and rapid detection of the intensity of the second vertically polarized wave and the second parallelly polarized wave.

[0013] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the lidar chip further includes: a polarization signal detection module manufactured on the polarization-insensitive platform; the polarization signal detection module is used to receive the feedback polarized light signal output from the feedback output terminal of the optical power distribution network and the local oscillator light signal output from the first optical coupler, and to obtain an output detection signal based on the feedback polarized light signal and the local oscillator light signal; the output detection signal is used to calculate detection information.

[0014] In this embodiment, the received feedback light signal is processed by a polarization signal detection module to obtain a detection signal for subsequent calculations, thereby reducing the complexity of subsequent processing of the data output by the lidar chip.

[0015] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the polarization signal detection module includes: a mixing unit and a balanced detection unit; the mixing unit is used to receive the feedback polarized light signal output from the feedback output terminal of the optical power distribution network and the local oscillator light signal output from the first optical coupler, and to separate the feedback vertically polarized wave and the feedback parallelly polarized wave included in the feedback polarized light signal, and to separate the first local oscillator light signal and the second local oscillator light signal included in the local oscillator light signal; the separated feedback vertically polarized wave is mixed with the first local oscillator light signal to obtain a first mixed signal; and the separated feedback parallelly polarized wave is mixed with the second local oscillator light signal to obtain a second mixed signal; the balanced detection unit is used to receive the first mixed signal and the second mixed signal, and to detect the first mixed signal and the second mixed signal to obtain an output detection signal; the output detection signal is used to calculate information such as the distance, velocity, and depolarization ratio of the object.

[0016] In this embodiment, the received feedback polarized light signal and local oscillator light signal are split and mixed by a mixing unit to obtain a mixed light signal after the two polarized light signals are mixed with their respective local oscillator lights. The detection signal can then be performed based on the two mixed light signals. This function can be achieved through a mixing unit and a balanced detection unit, reducing the complexity of the circuit.

[0017] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the mixing unit includes: a second polarization beamsplitter, a third polarization beamsplitter, a first mixer, and a second mixer; the second polarization beamsplitter is used to receive the feedback polarized light signal and separate the feedback vertically polarized wave and the feedback parallelly polarized wave included in the feedback polarized light signal; the third polarization beamsplitter is used to receive the local oscillator light signal and separate the local oscillator light signal including the first local oscillator light signal and the second local oscillator light signal; the first mixer is used to receive the feedback vertically polarized wave and the first local oscillator light signal, and mix the feedback vertically polarized wave and the first local oscillator light signal to obtain the first mixed signal; the second mixer is used to receive the feedback parallelly polarized wave and the second local oscillator light signal, and mix the feedback parallelly polarized wave and the second local oscillator light signal to obtain the second mixed signal.

[0018] In this embodiment, the required functions of the mixing unit can be achieved by the cooperation of two polarization beam splitters and two mixers, thereby reducing the complexity of the circuit.

[0019] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the balance detection unit includes: a first balance detector and a second balance detector; the first balance detector is used to receive and detect the first mixing signal, obtain and output a first output detection signal; the second balance detector is used to receive and detect the second mixing signal, obtain and output a second output detection signal; wherein, the output detection signal includes the first output detection signal and the second output detection signal.

[0020] In this embodiment, two balanced detectors are used to detect the two mixed optical signals respectively, thereby obtaining two sets of detection signals quickly and accurately.

[0021] In conjunction with the technical solution provided in the first aspect above, in some possible implementations, the polarization-insensitive platform is a 3μm SOI platform.

[0022] In this embodiment, due to the polarization insensitivity of the 3μm SOI platform, the difference between the emission angles of the emitted vertically polarized wave and the parallelly polarized wave is less than 0.5°. This meets the resolution requirements for object detection in applications such as industrial inspection and blind spot radar. Therefore, these two polarized light signals can be considered as detecting the same target.

[0023] Secondly, this application provides a detection device, comprising: a lidar chip, a signal detection circuit, and a polarized light generating circuit as described in the first aspect and / or in combination with any possible embodiment of the first aspect; the output terminal of the polarized light generating circuit is connected to the input terminal of the lidar chip, the polarized light generating circuit is used to generate an input light signal and transmit the input light signal to the lidar chip; the connection between the output terminal of the lidar chip and the signal detection circuit enables the signal detection circuit to perform detection data calculation based on the signal output by the lidar chip.

[0024] In conjunction with the technical solution provided in the second aspect above, in some possible implementations, the polarized light generating circuit includes: a laser and a polarization controller; the laser is used to generate an initial optical signal; and the polarization controller is used to generate an input optical signal including a polarized optical signal based on the initial optical signal.

[0025] In conjunction with the technical solution provided in the second aspect above, in some possible implementations, the lidar chip is a lidar chip including a balance detection module; the polarization controller is further used to adjust the ratio of vertically polarized waves and parallelly polarized waves in the input optical signal according to the first signal and the second signal output by the balance detection module in the lidar chip.

[0026] In this embodiment, the first signal characterizes the intensity of the second vertically polarized wave, and the second signal characterizes the intensity of the second parallelly polarized wave. Both the second vertically polarized wave and the second parallelly polarized wave are separated from the input optical signal. Therefore, the first and second signals can be used as the basis for the polarization controller to adjust the ratio of vertically polarized waves to parallelly polarized waves in the input optical signal, thereby maintaining the balance of polarized light signals in the input optical signal. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a first type of lidar chip shown in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a second type of lidar chip shown in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a third type of lidar chip shown in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the fourth type of lidar chip shown in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the fifth type of lidar chip shown in the embodiments of this application; Figure 6 This is a schematic diagram of the structure of the sixth type of lidar chip shown in the embodiments of this application; Figure 7 This is a structural block diagram of a detection device shown in an embodiment of this application.

[0029] Reference numerals: 100-LiDAR chip; 110-First optical coupler; 120-Optical power distribution network; 130-Phase shifter; 140-Grate antenna array; 150-Second optical coupler; 160-Balance detection module; 161-First polarization beam splitter; 162-First photodetector; 163-Second photodetector; 170-Polarization signal detection module; 171-Mixer unit; 1711-Second polarization beam splitter; 1712-Third polarization beam splitter; 1713-First mixer; 1714-Second mixer; 172-Balance detection unit; 1721-First balance detector; 1722-Second balance detector; 200-Signal detection circuit; 300-Polarized light generation circuit. Detailed Implementation

[0030] The terms “first,” “second,” “third,” etc., are used only for distinguishing descriptions and do not indicate a sequence number, nor should they be interpreted as indicating or implying relative importance.

[0031] In the description of this application, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” shall be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; as a mechanical connection or an electrical connection; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components.

[0032] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings.

[0033] Please see Figure 1 , Figure 1 The present invention provides a structural block diagram of a lidar chip, which includes a first optical coupler 110, an optical power distribution network 120, multiple phase shifters 130, and a grating antenna array 140 fabricated on a polarization-insensitive platform.

[0034] Optionally, the polarization-insensitive platform can be a 3μm SOI (Silicon-on-Insulator) platform, etc.

[0035] The first optical coupler 110 is used to receive the input optical signal, separate the input optical signal into a local oscillator signal and a polarized optical signal, transmit the separated polarized optical signal to the optical power distribution network 120, and output the local oscillator signal. The polarized optical signal includes vertically polarized waves and parallelly polarized waves.

[0036] The first optical coupler 110 can be any existing type of optical coupler structure, as long as it can separate the local oscillator optical signal and the polarized optical signal included in the input optical signal. The specific structure of the first optical coupler 110 is not limited here.

[0037] The input optical signal includes a local oscillator signal and a polarized optical signal. The local oscillator signal includes a first local oscillator signal and a second local oscillator signal, and the polarized optical signal includes a vertically polarized wave and a parallel-polarized wave. Specifically, the second local oscillator signal is the local oscillator signal corresponding to the parallel-polarized wave, and the first local oscillator signal is the local oscillator signal corresponding to the vertically polarized wave.

[0038] Optical power distribution network 120 is used to transmit polarized light signals to multiple phase shifters 130. Each phase shifter 130 is used to perform phase shifting processing on the received polarized light signals.

[0039] The optical power distribution network 120 (ODN) is a structure responsible for providing a transmission channel for optical signals and implementing power distribution. The specific structure of the optical power distribution network 120 is well known to those skilled in the art and will not be described in detail here for the sake of brevity.

[0040] The number of phase shifters 130 can be set according to actual needs. One phase shifter 130 is typically connected to one of the grating antennas in the grating antenna array 140. The phase shifter 130 is used to adjust the optical phase of the received optical signal.

[0041] The specific methods for achieving spatial control of the input optical signal through the phase shifter 130, the optical power distribution network 120, and the grating antenna array 140 are well known to those skilled in the art and will not be elaborated here for the sake of brevity.

[0042] The grating antenna array 140 is used to transmit each phase-shifted polarized light signal. The grating antenna array 140 is also used to receive feedback polarized light signals, which are transmitted to the optical power distribution network 120 through multiple phase shifters 130. The optical power distribution network 120 is also used to output the feedback polarized light signals received by the grating antenna array 140.

[0043] The grating antenna array 140 can be an existing waveguide grating antenna array 140 that can be set on a polarization-insensitive platform such as an SOI platform. Its specific structure and implementation are well known to those skilled in the art, and will not be described in detail here for the sake of brevity.

[0044] The lidar chip may consist of only a first optical coupler 110, an optical power distribution network 120, multiple phase shifters 130, and a grating antenna array 140.

[0045] Alternatively, in one implementation, the lidar chip further includes a second optical coupler 150 fabricated on a polarization-insensitive platform. For clarity, please refer to [link to relevant documentation]. Figure 2 .

[0046] The second optical coupler 150 is used to receive the input optical signal, split the received input optical signal into a first input optical signal and a second input optical signal according to a preset ratio, transmit the first input optical signal to the first optical coupler 110, and output the second input optical signal. The second input optical signal is used to detect whether the polarized light signal in the input optical signal is balanced.

[0047] Optionally, the preset ratio (i.e., the splitting ratio) of the first input optical signal and the second input optical signal split by the second optical coupler 150 can be set according to actual needs.

[0048] For example, the ratio of the first input optical signal to the second input optical signal can be set to 9:1. Alternatively, other ratios can be used, such as 19:1, 4:1, etc. This example is for illustrative purposes only; the splitting ratio of the first and second input optical signals split by the second optical coupler 150 is not limited to the example shown here.

[0049] In one embodiment, when the lidar chip includes a second optical coupler 150, the lidar chip can also be fabricated as a balance detection module 160 on a polarization-insensitive platform. For clarity, please refer to [link to relevant documentation]. Figure 2 .

[0050] The balance detection module 160 is used to receive the second input optical signal output by the second optical coupler 150, and detect the intensity of the second vertically polarized wave and the second parallelly polarized wave included in the polarized light signal in the second input optical signal, so as to obtain a first signal characterizing the intensity of the second vertically polarized wave and a second signal characterizing the intensity of the second parallelly polarized wave.

[0051] The balance detection module 160 receives the second input optical signal to obtain a first signal characterizing the intensity of the second vertically polarized wave and a second signal characterizing the intensity of the second parallelly polarized wave. This allows for subsequent detection of whether the polarized light signals in the input optical signal are balanced based on the first and second optical signals.

[0052] Optionally, the balance detection module 160 may include a first polarization beam splitter 161, a first photodetector 162, and a second photodetector 163. For easier understanding, please refer to [link to documentation]. Figure 3 .

[0053] like Figure 3 As shown, the first polarization beam splitter 161 is used to receive the second input optical signal output from the second output terminal of the second optical coupler 150, and separate the polarization signal in the second input optical signal, including the second vertically polarized wave and the second parallelly polarized wave. The separated second vertically polarized wave is transmitted to the first photodetector 162, and the separated second parallelly polarized wave is transmitted to the second photodetector 163.

[0054] The first polarizing beam splitter 161 (PBS) splits the incident light into two linearly polarized beams with orthogonal polarization directions. The structure of the first polarizing beam splitter 161 can be any existing type of polarizing beam splitter, and its specific structure is not limited here.

[0055] The first photodetector 162 is used to detect the intensity of the second vertically polarized wave and output a first signal.

[0056] The second photodetector 163 is used to detect the intensity of the second parallel polarized wave and output a second signal.

[0057] The first photodetector 162 and the second photodetector 163 are both devices used to convert optical signals into electrical signals, that is, both the first signal and the second signal are electrical signals.

[0058] A photodetector (PD) is a photoelectric device based on the photoelectric effect, capable of converting light signals into electrical signals. The first photodetector 162 and the second photodetector 163 can be any existing type of photodetector structure, as long as they can achieve the corresponding function.

[0059] In one implementation, the lidar chip may further include a polarization signal detection module 170 fabricated on a polarization-insensitive platform. For clarity, please refer to [link to relevant documentation]. Figure 4 .

[0060] The polarization signal detection module 170 is used to receive the feedback polarized light signal output from the feedback output terminal of the optical power distribution network 120 and the local oscillator light signal output from the first optical coupler 110, and to obtain the output detection signal based on the feedback polarized light signal and the local oscillator light signal; the output detection signal is used to calculate the detection information.

[0061] This application uses a polarization signal detection module 170 to process the received feedback optical signal to obtain a detection signal for subsequent calculations, thereby reducing the complexity of subsequent processing of the data output by the lidar chip.

[0062] Optionally, the polarization signal detection module 170 may include a mixing unit 171 and a balance detection unit 172.

[0063] The mixing unit 171 is used to receive the feedback polarized light signal output from the feedback output terminal of the optical power distribution network 120 and the local oscillator light signal output from the first optical coupler 110, and to separate the feedback vertically polarized wave and the feedback parallelly polarized wave included in the feedback polarized light signal, and to separate the first local oscillator light signal and the second local oscillator light signal included in the local oscillator light signal; to mix the separated feedback vertically polarized wave with the first local oscillator light signal to obtain a first mixed signal; and to mix the separated feedback parallelly polarized wave with the second local oscillator light signal to obtain a second mixed signal.

[0064] Optional, such as Figure 5 As shown, the mixing unit 171 may include a second polarization beamsplitter 1711, a third polarization beamsplitter 1712, a first mixer 1713, and a second mixer 1714. By cooperating with the two polarization beamsplitters and the two mixers, the required functions of the mixing unit 171 can be achieved, thereby reducing the complexity of the circuit.

[0065] The second polarization beam splitter 1711 is used to receive the feedback polarized light signal and separate the feedback vertically polarized wave and the feedback parallel polarized wave included in the feedback polarized light signal.

[0066] The third polarization beam splitter 1712 is used to receive the local oscillator light signal and separate the first local oscillator light signal and the second local oscillator light signal included in the local oscillator light signal.

[0067] The specific implementation and structure of the second polarization beam splitter 1711 and the third polarization beam splitter 1712 are the same as those of the first polarization beam splitter 161 mentioned above. For the sake of brevity, they will not be described in detail here.

[0068] The first mixer 1713 is used to receive the feedback vertically polarized wave and the first local oscillator light signal, and mix the feedback vertically polarized wave and the first local oscillator light signal to obtain the first mixed signal.

[0069] The specific structure of the first mixer 1713 can be selected according to actual needs, such as a 180° Mixer mixer, etc. There are no restrictions on its specific structure here.

[0070] The second mixer 1714 is used to receive the feedback parallel polarized wave and the second local oscillator light signal, and mix the feedback parallel polarized wave and the second local oscillator light signal to obtain the second mixed signal.

[0071] The specific implementation and structure of the second mixer 1714 are the same as those of the first mixer 1713 mentioned above, and will not be repeated here for the sake of brevity.

[0072] The balance detection unit 172 is used to receive the first mixing signal and the second mixing signal, and to detect the first mixing signal and the second mixing signal to obtain the output detection signal; the output detection signal is used to calculate information such as the distance, speed and depolarization ratio of the object.

[0073] In one implementation, such as Figure 5 As shown, the balance detection unit 172 may include: a first balance detector 1721 and a second balance detector 1722.

[0074] The first balanced detector 1721 is used to receive and detect the first mixing signal, and obtain and output the first output detection signal.

[0075] The second balanced detector 1722 is used to receive and detect the second mixing signal, obtain and output a second output detection signal. The output detection signal includes a first output detection signal and a second output detection signal.

[0076] The specific structure and principle of the Balanced Photodetector (BPD) are well known to those skilled in the art, and will not be described in detail here for the sake of brevity.

[0077] In one implementation, the lidar chip may consist only of a first optical coupler 110, an optical power distribution network 120, multiple phase shifters 130, a grating antenna array 140, and a polarization signal detection module 170, all manufactured on a polarization-insensitive platform.

[0078] Alternatively, the lidar chip may include a first optical coupler 110, an optical power distribution network 120, multiple phase shifters 130, a grating antenna array 140, a polarization signal detection module 170, and a second optical coupler 150, all manufactured on a polarization-insensitive platform.

[0079] Alternatively, the lidar chip may include a first optical coupler 110, an optical power distribution network 120, multiple phase shifters 130, a grating antenna array 140, a polarization signal detection module 170, a second optical coupler 150, and a balance detection module 160, all manufactured on a polarization-insensitive platform.

[0080] The specific connection relationships between the various components in the different implementations of the aforementioned lidar chips have been clearly described above and will not be repeated here for the sake of brevity.

[0081] For ease of understanding, the following example is used: a lidar chip including a first optical coupler 110, an optical power distribution network 120, multiple phase shifters 130, a grating antenna array 140, a polarization signal detection module 170, a second optical coupler 150, and a balance detection module 160.

[0082] like Figure 6 As shown, the input terminal of the second optical coupler 150 is used to receive the input optical signal, and the first output terminal of the second optical coupler 150 is connected to the input terminal of the first optical coupler 110. The second optical coupler 150 is used to split the received input optical signal into a first input optical signal and a second input optical signal according to a preset ratio, and transmit the first input optical signal to the first optical coupler 110 through the first output terminal, and output the second input optical signal through the second output terminal. The preset ratio is 9:1, that is, the ratio of the light intensity of the first input optical signal to the light intensity of the second input optical signal is 9:1.

[0083] The input terminal of the first optical coupler 110 is connected to the first output terminal of the second optical coupler 150, the first output terminal of the first optical coupler 110 is connected to the input terminal of the optical power distribution network 120, and the second output terminal of the first optical coupler 110 is connected to the input terminal of the third polarization beam splitter 1712. The first optical coupler 110 is used to separate the input optical signal, including the local oscillator signal and the polarized optical signal, and transmit the separated polarized optical signal to the optical power distribution network 120, and transmit the local oscillator signal to the third polarization beam splitter 1712.

[0084] The optical power distribution network 120 is connected to each phase shifter 130, and each phase shifter 130 is also connected to a grating antenna in the grating antenna array 140.

[0085] The grating antenna array 140 is also used to receive feedback polarized light signals, which are transmitted to the optical power distribution network 120 through multiple phase shifters 130. The optical power distribution network 120 is also used to output the feedback polarized light signals received by the grating antenna array 140.

[0086] The input terminal of the second polarization beam splitter 1711 is connected to the feedback output terminal of the optical power distribution network 120, the first output terminal of the second polarization beam splitter 1711 is connected to the first input terminal of the first mixer 1713, and the second output terminal of the second polarization beam splitter 1711 is connected to the first input terminal of the second mixer 1714. The second polarization beam splitter 1711 is used to separate the feedback polarized light signal, including the feedback vertically polarized wave and the feedback parallelly polarized wave.

[0087] The first output terminal of the third polarization beam splitter 1712 is connected to the second input terminal of the first mixer 1713, and the second output terminal of the third polarization beam splitter 1712 is connected to the second input terminal of the second mixer 1714; the third polarization beam splitter 1712 is used to separate the local oscillator signal, which includes the first local oscillator signal and the second local oscillator signal.

[0088] The output of the first mixer 1713 is connected to the first input of the balanced detection unit 172. The first mixer 1713 is used to mix the received feedback vertical polarization wave with the first local oscillator light signal to obtain the first mixed signal.

[0089] The output of the second mixer 1714 is connected to the second input of the balanced detection unit 172. The second mixer 1714 is used to mix the received feedback parallel polarized wave with the second local oscillator light signal to obtain the second mixed signal.

[0090] The input terminal of the first balanced detector 1721 is connected to the output terminal of the first mixer 1713. The first balanced detector 1721 is used to detect the first mixing signal and obtain and output the first output detection signal.

[0091] The input terminal of the second balanced detector 1722 is connected to the output terminal of the second mixer 1714. The second balanced detector 1722 is used to detect the second mixing signal, obtain and output the second output detection signal.

[0092] The input terminal of the first polarization beam splitter 161 is connected to the second output terminal of the second optical coupler 150, the first output terminal of the first polarization beam splitter 161 is connected to the first detector, and the second output terminal of the first polarization beam splitter 161 is connected to the second detector.

[0093] The first polarization beam splitter 161 is used to separate the polarized light signal in the second input light signal, including the second vertically polarized wave and the second parallelly polarized wave, and transmit the separated second vertically polarized wave to the first detector and the separated second parallelly polarized wave to the second detector.

[0094] The first detector is used to detect the intensity of the second vertically polarized wave and output a first signal.

[0095] The second detector is used to detect the intensity of the second parallel polarized wave and output a second signal.

[0096] Figure 6 The lidar chip shown is only one embodiment of the lidar chip provided in this application, and the lidar chip shown in this application is not limited to... Figure 6 The implementation method shown.

[0097] Based on the same technical concept, this application also provides a detection device. For example... Figure 7 As shown, the detection device includes a lidar chip 100, a signal detection circuit 200, and a polarized light generation circuit 300.

[0098] The specific structure and working logic of the lidar chip 100 have been clearly described above, and will not be repeated here for the sake of brevity.

[0099] The output terminal of the polarization light generating circuit 300 is connected to the input terminal of the lidar chip 100. The polarization light generating circuit 300 is used to generate an input light signal and transmit the input light signal to the lidar chip 100.

[0100] The polarized light generating circuit 300 can be any existing circuit capable of generating the input light signal. The specific function and implementation method of the input light signal have been clearly described above, and will not be repeated here for the sake of brevity.

[0101] Optionally, the polarization light generating circuit 300 may include a laser and a polarization controller.

[0102] A laser is used to generate an initial optical signal. A polarization controller is used to generate an input optical signal, including a polarized optical signal, based on the initial optical signal.

[0103] The specific type and model of the laser can be selected according to actual needs; there are no restrictions on its specific type and model here.

[0104] A polarization controller is an optical device used to precisely control the polarization state of light waves. Its specific implementation and structure are well known to those skilled in the art, and will not be described in detail here for the sake of brevity.

[0105] In one embodiment, when the lidar chip 100 includes a second optical coupler 150 and a balance detection module 160, the polarization controller is further used to adjust the ratio of vertically polarized waves and parallelly polarized waves in the input optical signal according to the first signal and the second signal output by the balance detection module 160.

[0106] In other words, the polarization controller receives the first and second signals output by the lidar chip 100, and adjusts the ratio of vertically polarized waves to parallelly polarized waves in the input optical signal to make the first and second signals approach equal. The closer the first and second signals are, the smaller the deviation between the vertically polarized waves and parallelly polarized waves in the input optical signal.

[0107] For example, if the first signal is greater than the second signal, it indicates that the intensity of the vertically polarized wave in the input optical signal is greater than the intensity of the parallelly polarized wave. Therefore, it is necessary to reduce the intensity of the vertically polarized wave in the input optical signal and increase the intensity of the parallelly polarized wave.

[0108] Conversely, when the first signal is less than the second signal, it indicates that the intensity of the vertically polarized wave in the input optical signal is less than the intensity of the parallelly polarized wave. Therefore, it is necessary to increase the intensity of the vertically polarized wave in the input optical signal and decrease the intensity of the parallelly polarized wave.

[0109] The output terminal of the lidar chip 100 is connected to the signal detection circuit 200 so that the signal detection circuit 200 can perform detection data calculation based on the signal output by the lidar chip 100.

[0110] The signal detection circuit 200 can be any circuit capable of processing the signal output by the lidar chip 100.

[0111] Optionally, when the signal output by the lidar chip 100 is a feedback polarized light signal and a local oscillator light signal, the signal detection circuit 200 may include a polarization signal detection circuit and a processor.

[0112] The polarization signal detection circuit is implemented in the same way as the aforementioned polarization signal detection module 170, except that the polarization signal detection circuit is a peripheral circuit of the lidar chip. For brevity, details will not be elaborated here.

[0113] The processor can be an electronic device that can calculate the detection information based on the output detection signal, such as a CPU (Central Processing Unit), NP (Network Processor), etc.; it can also be a DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0114] After receiving the first and second output detection signals, the processor calculates the distance and velocity information of the object by detecting the beat frequency signals of the first and second output detection signals. Based on the photocurrent values ​​of the first and second output detection signals, the optical power values ​​of the two polarized lights are calculated. Therefore, the depolarization ratio of the object can be analyzed based on the optical power values, which serves as a basis for detecting the material properties of the object.

[0115] The depolarization ratio can be calculated using the following formula: Where E2(t) is the intensity of the feedback polarized light signal at time t, and E1(t) is the intensity of the first input light signal at time t. ∝ indicates a direct proportional relationship, σ is the backscattering coefficient, and p is the ratio of light intensities whose polarization direction changes to orthogonal direction (depolarization ratio).

[0116] E2(t) can be expressed by the formula: The calculation yielded the following result. It is the light intensity of the parallel polarized wave in the feedback polarized light signal. It is the light intensity of the vertically polarized wave in the feedback polarized light signal. It is the light intensity of the parallel polarized wave in the feedback polarized light signal at time t. It is the light intensity of the vertically polarized wave in the feedback polarized light signal at time t. , It can be calculated based on the first output detection signal and the second output detection signal respectively.

[0117] E1(t) can be expressed by the formula: The calculation yielded the following result. It is the light intensity of the parallel polarized wave in the first input optical signal. It is the light intensity of the vertically polarized wave in the first input optical signal. It is the light intensity of the parallel polarized wave in the first input optical signal at time t. It is the light intensity of the vertically polarized wave in the first input optical signal at time t. , It can be determined based on the input optical signal.

[0118] In the case where the lidar chip 100 does not include a second optical coupler, The intensity of the vertically polarized wave in the input optical signal. The intensity of the parallel polarized wave in the input optical signal.

[0119] In the case where the lidar chip 100 includes a second optical coupler, according to The intensity of the vertically polarized wave in the first input optical signal. The intensity of the parallel-polarized wave in the first input optical signal is given. The intensity of the parallel-polarized wave and the intensity of the vertically polarized wave in the first input optical signal can be calculated based on the input optical signal and a preset ratio (the splitting ratio of the second optical coupler).

[0120] The specific methods for calculating information such as the distance, velocity, and depolarization ratio of an object based on the first and second output detection signals are well known to those skilled in the art and will not be elaborated here for the sake of brevity.

[0121] Optionally, when the signal output by the lidar chip 100 is an output detection signal (including the aforementioned first output detection signal and second output detection signal), the signal detection circuit 200 may include a processor.

[0122] The implementation method and principle of the processor have been clearly described above, and will not be repeated here for the sake of brevity.

[0123] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A lidar chip, characterized in that, include: A first optical coupler, an optical power distribution network, multiple phase shifters, and a grating antenna array are fabricated on a polarization-insensitive platform. The first optical coupler is used to receive an input optical signal, separate the input optical signal into a local oscillator signal and a polarized optical signal, transmit the separated polarized optical signal to the optical power distribution network, and output the local oscillator signal; the polarized optical signal includes a vertically polarized wave and a parallelly polarized wave; The optical power distribution network is used to transmit the polarized light signal to the plurality of phase shifters; each phase shifter is used to perform phase shifting processing on the received polarized light signal; The grating antenna array is used to transmit the polarized light signal after each phase shifting process; The grating antenna array is also used to receive feedback polarized light signals, which are transmitted to the optical power distribution network through the plurality of phase shifters. The optical power distribution network is also used to output the feedback polarized light signals received by the grating antenna array.

2. The lidar chip according to claim 1, characterized in that, The lidar chip also includes: Fabricate a second optical coupler on the polarization-insensitive platform; The second optical coupler is used to receive the input optical signal, split the received input optical signal into a first input optical signal and a second input optical signal according to a preset ratio, transmit the first input optical signal to the first optical coupler, and output the second input optical signal. The second input optical signal is used to detect whether the polarized light signal in the input optical signal is balanced.

3. The lidar chip according to claim 2, characterized in that, The lidar chip also includes: A balance detection module is manufactured on the polarization-insensitive platform; The balance detection module is used to receive the second input optical signal output by the second optical coupler, and detect the intensity of the second vertically polarized wave and the second parallelly polarized wave included in the polarized light signal in the second input optical signal, so as to obtain a first signal characterizing the intensity of the second vertically polarized wave and a second signal characterizing the intensity of the second parallelly polarized wave.

4. The lidar chip according to claim 3, characterized in that, The balance detection module includes: First polarization beam splitter, first photodetector, second photodetector; The first polarization beam splitter is used to receive the second input optical signal output from the second output terminal of the second optical coupler, and to separate the polarization signal in the second input optical signal, including the second vertically polarized wave and the second parallelly polarized wave, and to transmit the separated second vertically polarized wave to the first photodetector and the separated second parallelly polarized wave to the second photodetector. The first photodetector is used to detect the intensity of the second vertically polarized wave and output the first signal; The second photodetector is used to detect the intensity of the second parallel polarized wave and output the second signal.

5. The lidar chip according to claim 1, characterized in that, The lidar chip also includes: A polarization signal detection module is manufactured on the polarization-insensitive platform; The polarization signal detection module is used to receive the feedback polarized light signal output from the feedback output terminal of the optical power distribution network and the local oscillator light signal output from the first optical coupler, and to obtain an output detection signal based on the feedback polarized light signal and the local oscillator light signal; the output detection signal is used to calculate detection information.

6. The lidar chip according to claim 5, characterized in that, The polarization signal detection module includes: Mixer unit, balanced detection unit; The mixing unit is used to receive the feedback polarized light signal output from the feedback output terminal of the optical power distribution network and the local oscillator light signal output from the first optical coupler, and to separate the feedback vertically polarized wave and the feedback parallelly polarized wave included in the feedback polarized light signal, and to separate the first local oscillator light signal and the second local oscillator light signal included in the local oscillator light signal; to mix the separated feedback vertically polarized wave with the first local oscillator light signal to obtain a first mixed signal; and to mix the separated feedback parallelly polarized wave with the second local oscillator light signal to obtain a second mixed signal. The balanced detection unit is used to receive the first mixing signal and the second mixing signal, and to detect the first mixing signal and the second mixing signal to obtain an output detection signal; the output detection signal is used to calculate the distance, speed and depolarization ratio of the object.

7. The lidar chip according to claim 6, characterized in that, The mixing unit includes: Second polarization beam splitter, third polarization beam splitter, first mixer, second mixer; The second polarization beam splitter is used to receive the feedback polarized light signal and separate the feedback vertically polarized wave and the feedback parallel polarized wave included in the feedback polarized light signal; The third polarization beam splitter is used to receive the local oscillator light signal and separate the local oscillator light signal into a first local oscillator light signal and a second local oscillator light signal. The first mixer is used to receive the feedback vertically polarized wave and the first local oscillator light signal, and to mix the feedback vertically polarized wave and the first local oscillator light signal to obtain the first mixed signal; The second mixer is used to receive the feedback parallel polarized wave and the second local oscillator signal, and mix the feedback parallel polarized wave and the second local oscillator signal to obtain the second mixed signal.

8. The lidar chip according to claim 7, characterized in that, The balance detection unit includes: First balance detector, second balance detector; The first balanced detector is used to receive and detect the first mixing signal, obtain and output the first output detection signal; The second balanced detector is used to receive and detect the second mixing signal, obtain and output the second output detection signal; The output detection signal includes the first output detection signal and the second output detection signal.

9. The lidar chip according to any one of claims 1-8, characterized in that, The polarization-insensitive platform is a 3μm SOI platform.

10. A detection device, characterized in that, include: The lidar chip, signal detection circuit, and polarized light generation circuit as described in any one of claims 1-9; The output terminal of the polarization light generating circuit is connected to the input terminal of the lidar chip. The polarization light generating circuit is used to generate an input light signal and transmit the input light signal to the lidar chip. The connection between the output terminal of the lidar chip and the signal detection circuit enables the signal detection circuit to perform detection data calculation based on the signal output by the lidar chip.

11. The detection device according to claim 10, characterized in that, The polarized light generating circuit includes: Lasers, polarization controllers; The laser is used to generate the initial optical signal; The polarization controller is used to generate the input optical signal, which includes polarized optical signals, based on the initial optical signal.

12. The detection device according to claim 11, characterized in that, The lidar chip is the lidar chip according to claim 3; The polarization controller is also used to adjust the ratio of vertically polarized waves and parallelly polarized waves in the input optical signal according to the first signal and the second signal output by the balance detection module in the lidar chip.

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