Optical transceiver assembly for lidar, lidar, and terminal device

Abstract

The present disclosure relates to an optical transceiver assembly for a lidar, a lidar, and a terminal device. The optical transceiver assembly comprises a transmitter, a receiver, a polarization beam splitter, a phase modulator, a window, and one or more optical members. The transmitter is configured to transmit a light beam having a first polarization state. The receiver is configured to receive an echo generated after the light beam is reflected by an object. The echo received by the receiver has a second polarization state. The first polarization state has a polarization direction different from that of the second polarization state. The polarization beam splitter is configured to change a direction of the light beam or the echo. The phase modulator is configured to modulate phases of the light beam and the echo. The light beam is transmitted to the exterior of the lidar via the window, and the echo enters the interior of the lidar via the window. The phase modulator is located between the one or more optical members and the window on an optical path.

Description

Optical transceiver components for lidar, lidar, and terminal devices.

[0001] This disclosure claims priority to Chinese Patent Application No. 202411950334.5, filed on December 26, 2024, entitled "Optical transceiver assembly for lidar, lidar and terminal device", the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure relates to the field of photoelectric detection, and more specifically to an optical transceiver assembly for lidar, lidar, and terminal equipment. Background Technology

[0003] LiDAR is a radar system that uses emitted light beams to detect the position, velocity, and other characteristics of objects. Due to its advantages such as high resolution, strong resistance to active interference, good detection performance, small size, and light weight, LiDAR is widely used in fields such as autonomous driving, transportation communication, drones, intelligent robots, and resource exploration.

[0004] In lidar systems that use polarized beams, optical components in the lidar's optical system may cause the polarized beam to depolarize, affecting the lidar's detection performance. Summary of the Invention

[0005] This disclosure provides an optical transceiver assembly for lidar, which helps to improve the detection performance of lidar.

[0006] According to a first aspect of this disclosure, an optical transceiver assembly for a lidar is provided. The optical transceiver assembly includes: a transmitter configured to emit a light beam having a first polarization state; a receiver configured to receive an echo generated after the light beam is reflected from an object, wherein the echo received by the receiver has a second polarization state, the polarization direction of the first polarization state being different from the polarization direction of the second polarization state; a polarization beam splitter configured to change the direction of the light beam or the echo; a phase modulator configured to modulate the phase of the light beam and the echo; a window through which the light beam is transmitted to the outside of the lidar and the echo enters the interior of the lidar; and one or more optical elements, the phase modulator being located in the optical path between the one or more optical elements and the window.

[0007] Optionally, the one or more optical components include at least one of a scanner, lens, mirror, filter, aperture, homogenizer, prism, and grating.

[0008] Optionally, the phase modulator includes at least one of a quarter-wave plate, a Faraday rotator, or a liquid crystal polymer.

[0009] Optionally, the phase modulator is located in the optical path between the polarization beam splitter and the window.

[0010] Optionally, the phase modulator is disposed on the surface of the window.

[0011] Optionally, the phase modulator includes a first region and a second region, and satisfies the following condition: the fast axis direction of the first region is different from the fast axis direction of the second region.

[0012] Optionally, the phase modulator comprises a liquid crystal polymer.

[0013] Optionally, the light beam includes a first light beam incident on the first region and a second light beam incident on the second region, wherein the phase modulator is configured such that a first angle between the first light beam and the fast axis direction of the first region is within a first preset range, and a second angle between the second light beam and the fast axis direction of the second region is within the first preset range.

[0014] Optionally, the first preset range includes a range between 40° and 50°.

[0015] Optionally, the phase modulator includes a first region and a second region, the beam includes a first beam incident on the first region and a second beam incident on the second region, wherein the phase modulator is configured as a curved phase modulator such that the first beam is incident substantially perpendicularly on the first region and the second beam is incident substantially perpendicularly on the second region.

[0016] Optionally, the optical element includes a scanner, and the phase modulator is located in the optical path between the scanner and the window.

[0017] Optionally, the scanner includes a reflective surface, and the phase modulator is disposed on the reflective surface of the scanner.

[0018] Optionally, the scanner is configured to change the exit direction of the beam along a first direction.

[0019] Optionally, the scanner is further configured to change the exit direction of the beam along a second direction, wherein the first direction and the second direction are perpendicular to each other.

[0020] Optionally, the scanner may include one two-dimensional scanner or two one-dimensional scanners.

[0021] Optionally, the one or more optical elements include an optical surface, and the angle between the fast axis direction of the optical surface and the light beam incident on the optical surface is within a second preset range.

[0022] Optionally, the second preset range includes a range between -15° and 15° or a range between 75° and 105°.

[0023] Optionally, the optical surface includes at least one of a refractive surface, a reflective surface, and a diffractive surface.

[0024] Optionally, the transmitter includes a laser configured to emit linearly polarized light having the first polarization state.

[0025] Optionally, at least two of the transmitter, the receiver, and the polarization beam splitter are integrated into a transceiver chip.

[0026] According to a second aspect of this disclosure, a lidar is provided. The lidar includes an optical transceiver assembly as described above; and a controller configured to: control the transmitter to emit the light beam; and calculate at least one of the distance to the object and its reflectivity based on the echo received by the receiver.

[0027] According to a third aspect of this disclosure, a terminal device is provided, including the lidar as described above. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be introduced as examples below. The drawings described below are merely embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. The drawings are used to provide a further understanding of this disclosure and constitute a part of the specification. They are used together with the embodiments of this disclosure to explain this disclosure and do not constitute a limitation of this disclosure. In the drawings:

[0029] Figure 1 shows an example structural block diagram of an exemplary lidar consistent with some embodiments of this disclosure.

[0030] Figure 2 shows a structural block diagram of an exemplary vehicle system consistent with some embodiments of this disclosure.

[0031] Figure 3 shows a schematic diagram of an exemplary device for lidar.

[0032] Figure 4 shows a schematic diagram of the debiasing effect.

[0033] Figure 5 shows a schematic block diagram of an optical transceiver assembly for a lidar according to a first exemplary embodiment consistent with some embodiments of this disclosure.

[0034] Figure 6 shows a schematic block diagram of a phase modulator consistent with some embodiments of this disclosure.

[0035] Figure 7 shows a schematic block diagram of an optical transceiver assembly for a lidar according to a second exemplary embodiment consistent with some embodiments of the present disclosure.

[0036] Figure 8 shows a schematic block diagram of an optical transceiver assembly for a lidar according to a third exemplary embodiment consistent with some embodiments of this disclosure.

[0037] Figure 9 shows a schematic block diagram of an optical transceiver assembly for a lidar according to a fourth exemplary embodiment consistent with some embodiments of the present disclosure.

[0038] Figure 10 shows a schematic block diagram of a phase modulator consistent with some embodiments of the present disclosure.

[0039] Figure 11 shows a schematic block diagram of an optical transceiver assembly for a lidar according to a fifth exemplary embodiment consistent with some embodiments of the present disclosure.

[0040] Figure 12 shows a schematic block diagram of an optical transceiver assembly for lidar according to a sixth exemplary embodiment consistent with some embodiments of the present disclosure. Detailed Implementation

[0041] The embodiments of this disclosure will be described below. It should be noted that, in order to provide a concise description of these embodiments, this specification cannot exhaustively describe all features of the actual embodiments. It should be understood that, in the actual implementation of any embodiment, changes may occur from one embodiment to another to achieve specific objectives. Furthermore, it is also understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content of this disclosure, some design, manufacturing, or production modifications based on the technical content disclosed in this disclosure are merely conventional technical means and should not be construed as insufficient content of this disclosure.

[0042] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar words used in this patent application description and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms “an” or “a” and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar words mean that the element or object preceding “comprising” or “including” encompasses the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The terms “connected,” “coupled,” or “linked” and similar words are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0043] Unless otherwise specified, all embodiments mentioned herein can be combined to form new technical solutions. Furthermore, unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0044] In this disclosure, the terms "or" and "and / or" describe the relationship between related objects and indicate a non-exclusive inclusion. For example, "A and / or B" and "A or B" can include: the presence of only "A", the presence of only "B", and the presence of both "A" and "B", where "A" and "B" can be singular or plural. As another example, "A, B, and / or C" and "A, B, or C" can include: the presence of only "A", the presence of only "B", the presence of only "C", the presence of both "A" and "B", the presence of both "A" and "C", the presence of both "B" and "C", and the presence of both "A", "B", and "C", where "A", "B", and "C" can be singular or plural. Furthermore, the symbol " / " in this disclosure indicates an "or" relationship between the related objects before and after the symbol. In this disclosure, the term "at least one A or B" has the same meaning as "A or B" described above. The term "at least one A, B or C" has the same meaning as "A, B or C" above.

[0045] LiDAR (Light Detection and Ranging) is a remote sensing technology that uses laser light to measure distances and create three-dimensional (3D) images of objects and landscapes. During object detection, the LiDAR emits a laser beam; upon encountering an object, the laser is reflected from the object's surface; the reflected light (called an echo) is received by the LiDAR and converted into an electrical signal. The LiDAR processes this electrical signal to determine information about the object, such as its distance, position, or velocity. The LiDAR system 110 can also be configured to create a real-time 3D model of the environment, which can be represented as a point cloud. A point cloud is a collection of 3D data points representing the surfaces of objects, structures, and the environment within a specific area. Each data point in the point cloud can be defined by its X, Y, and Z coordinates in space, representing its position in 3D space. Using point clouds, vehicles can accurately identify the positions of objects on the road, such as cars, pedestrians, and / or cyclists.

[0046] In some examples, LiDAR can generate point clouds, which simplifies and simplifies the processing of driver assistance algorithms. LiDAR provides high-resolution 3D vision for vehicles (such as intelligent vehicles), working in conjunction with cameras and radar to enhance the vehicle's perception capabilities to handle more complex road conditions (such as dark environments or unknown objects on highways). LiDAR can further provide high-performance automotive-grade LiDAR solutions, ensuring safer and smarter driver assistance, such as L2+ assisted driving. When configured, LiDAR can be widely used in passenger cars and commercial vehicles equipped with advanced driver assistance systems (ADAS) and / or autonomous driving (e.g., automated traffic). LiDAR can also be applied to any suitable end device, such as drones or robots. For example, LiDAR can support robotic applications such as delivery robots and logistics robots.

[0047] In some examples, LiDAR can be configured as a long-range LiDAR sensor with a long detection range, such as from hundreds of meters to thousands of meters. Long-range LiDAR sensors can detect and classify objects at long distances. They can be mounted on the roof of a vehicle (e.g., the front and / or rear roof) to provide an unobstructed view of the road ahead and / or behind, and to detect objects at greater distances. This is extremely useful for highway driving and for detecting distant objects as early as possible.

[0048] In some examples, LiDAR can be configured as a short-range LiDAR sensor with a shorter detection range, such as a few meters to tens of meters around the LiDAR, but a wider field of view (FOV), such as 60 degrees to 360 degrees horizontally. The wider FOV allows for the detection of nearby objects and provides a more comprehensive view of the surrounding environment / objects. Short-range LiDAR sensors can be mounted near or to the side of the vehicle's headlights to improve perception and assist in lane keeping and / or lane changing maneuvers.

[0049] In some examples, the lidar can be configured as a mid-range lidar sensor. Mid-range lidar sensors strike a balance between long-range and short-range lidar sensors in terms of detection range (e.g., from a few meters to several hundred meters) and field of view (e.g., from 30 degrees to 180 degrees horizontally). Mid-range lidar sensors can be mounted on the front bumper, side panels, or rear bumper to detect objects near the vehicle, making them suitable for parking and detecting nearby objects while driving in urban environments.

[0050] In some examples, a lidar system with multiple lidar sensors is deployed around the vehicle, with each lidar configured to have different detection ranges and fields of view to cover the area around the vehicle. In some embodiments, the lidar system includes one or more near-range lidar sensors and one or more mid-range lidar sensors. By combining lidar sensors at different locations on the vehicle, the lidar system can provide a comprehensive view of the environment. Data from these lidar sensors can be processed with data from other sensors, such as cameras and / or millimeter-wave radar, to make real-time decisions for safe and efficient autonomous driving. The combination of lidar sensors with different detection ranges, fields of view, and locations achieves a balance between long-range visibility and near-range object detection, while also considering aesthetics and cost.

[0051] In some examples, multiple lidar sensors are activated in a lidar system. In some embodiments, multiple lidar sensors are activated or deactivated depending on different scenarios or requirements. For example, when the vehicle is traveling at high speeds (e.g., above 40 mph), one or more short-range lidar sensors may be deactivated, while one or more long-range and mid-range lidar sensors may be activated. As another example, when the vehicle is traveling at lower speeds (e.g., below 40 mph), one or more long-range lidar sensors may be deactivated, while one or more short-range and mid-range lidar sensors may be activated. This effectively saves energy and extends the lifespan of the lidar system.

[0052] Figure 1 shows an example structural block diagram of an exemplary lidar consistent with some embodiments of this disclosure. Referring to Figure 1, the lidar 100 includes a laser emitting system 110, a laser receiving system 120, and a control and processing system 130. Optionally, the lidar 100 also includes a scanning system 140. The scanning system 140 may include a rotating optical engine, a rotating mirror, a reciprocating oscillating mirror or galvanometer (e.g., a MEMS mirror, a Galvo mirror, etc.), and other components that can direct the laser beam to different locations in the environment (e.g., prisms, gratings, diffractive optical elements, etc.).

[0053] The laser emitting system 110 emits a laser beam. Upon encountering an object 10, the beam is reflected from the surface of the object 10, forming an echo that returns to the lidar 100. The laser receiving system 120 receives the reflected echo and converts it into an electrical signal. This electrical signal is pre-processed to determine echo data, such as the echo reception time, and provided to the control and processing system 130. The control and processing system 130 processes the echo data to determine information about the object 10, such as its distance, position, or velocity. This process is repeated multiple times to create an accurate, real-time 3D environment map, such as a point cloud. Computers in terminal devices such as vehicles can then perform safe navigation based on this point cloud.

[0054] The laser emitting system 110 includes a driving circuit 112, a laser 114, and emitting optics 116. The laser 114 emits a laser beam under the drive of the driving circuit 112, and the beam exits through the emitting optics 116. The laser 114 may include a semiconductor laser, such as a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), or other semiconductor lasers capable of generating laser light. In some embodiments, the laser 114 may also include a fiber laser. The wavelength of the laser emitted by the laser 114 can be any one of 905nm, 940nm, 1310nm, 1440nm, or 1550nm; the laser 114 may also emit laser light of other wavelengths. The driving circuit 112 may include a driver integrated circuit, such as an analog chip or a digital-analog hybrid chip.

[0055] The laser receiving system 120 includes a receiving optics 122 and a receiver 124. The receiving optics 122 collects the echo reflected from an object and focuses the echo onto the receiver 124. The receiver 124 uses the photoelectric effect to convert the echo into an electrical signal. The receiver 124 may include a single-photon detector, such as an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), or a silicon photomultiplier (SiPM). The lidar 100 may also include a preprocessing circuit 150. This preprocessing circuit 150 may include digitization circuitry, such as an analog-to-digital converter (ADC), to convert analog signals into digital signals for supply to the control and processing system 130. Alternatively, the preprocessing circuit 150 may include a time-to-digital converter (TDC). The echo, detected and converted into an electrical signal by the receiver 124, is then provided to the TDC. Based on the received electrical signal, the TDC can determine the timing information (e.g., timestamp) of the echo and convert the timing information into a digital signal for the control and processing system 130. The preprocessing circuit 150 may also include analog front-end circuitry for channel selection and analog signal amplification. In some embodiments, the preprocessing circuit 150 may be implemented as a system-on-chip (SOC) or application-specific integrated circuit (ASIC). The transmitting optics 116 and receiving optics 122 include, for example, one or more optical components such as lenses / lens groups, mirrors, filters, beam splitters, apertures, and homogenizers. The transmitting optics 116 and receiving optics 122 may be independently configured optical components or may be fully or partially multiplexed. For example, the transmitting optics 116 and receiving optics 122 may include at least one of a common lens, a common lens group, a common mirror, a common aperture, and a common beam splitter. The laser emitted by laser 114 and the echo reflected by the object can pass through at least one of a common lens, a common lens group, a common mirror, a common aperture, and a common beam splitter.

[0056] The control and processing system 130 may include an information processing circuit 132 and a light source control circuit 134. The information processing circuit 132 processes electrical signals to determine information about the object. For example, the information processing circuit 132 may include circuits implemented using an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as a field-programmable gate array (FPGA), a microcontroller unit (MCU), or a digital signal processor (DSP). Alternatively, the information processing circuit 132 may include a central processing unit (CPU). The light source control circuit 134 sends control signals to the excitation source to control the excitation source to drive the laser to emit light, achieving pulsed laser emission. For example, the light source control circuit 134 may send timing signals to control the laser emission timing. Furthermore, the light source control circuit 134 may add pulse coding functionality by controlling one or more of the pulse interval, pulse intensity, and pulse width, thereby enhancing the anti-interference capability of the lidar. The light source control circuit 134 and the information processing circuit 132 can be integrated together, for example, integrated into a main control chip, or they can each be independent or partially independent chips. When the lidar 100 includes a scanning system 140, the control and processing system 130 can also include a scanning control circuit 136 for controlling the scanning system. The scanning control circuit 136 can be integrated with one or all of the light source control circuit 134 and the information processing circuit 132. For example, the scanning control circuit 136, the light source control circuit 134, and the information processing circuit 132 can be integrated into a main control chip; or they can each be independent or partially independent chips. In some embodiments, the control and processing system 130 can be implemented as a system on chip (SOC) or an application-specific integrated circuit (ASIC).

[0057] In applications, lidar can be installed on terminal devices to transmit the detected sensing data. The terminal devices then use this data to perform one or more functions, such as analysis, decision-making, or control. Terminal devices include, for example, vehicles, ships, aircraft (e.g., flying vehicles or drones), and robots (e.g., industrial robots or home robots).

[0058] Figure 2 illustrates a structural block diagram of an exemplary vehicle system consistent with some embodiments of this disclosure. Referring to Figure 2, the vehicle system 200 includes a sensor system 202, a perception system 204, a planning system 206, and a control system 208. The vehicle system 200 may have autonomous capabilities, for example, having at least one function, characteristic, device, and / or similar device that enables the vehicle to operate partially or fully without human intervention, including but not limited to fully autonomous vehicles (e.g., abandoning vehicles dependent on human intervention), highly autonomous vehicles (e.g., abandoning vehicles dependent on human intervention in certain situations), and / or similar devices. The sensor system 202 includes one or more devices, such as lidar 202a, radar 202b, camera 202c, sonar 202d, global positioning system (GPS) 202e, and inertial measurement unit (IMU) 202f. Lidar 202a may include lidar sensors, such as long-range lidar sensors, mid-range lidar sensors, or short-range lidar sensors. In some embodiments, sensor system 202 uses one or more devices included in sensor system 202 to generate environment-related data. The data generated by sensor system 202 can be used by one or more systems to observe the environment in which the vehicle is located.

[0059] In some examples, the perception system 204 receives data associated with at least one object in the environment and classifies the at least one object. In some examples, the perception system 204 receives image data (e.g., point clouds) associated with objects captured by at least one lidar sensor. In such examples, the perception system 204 classifies objects based on groupings of objects (e.g., bicycles, vehicles, traffic signs, pedestrians and / or the like). In some embodiments, the perception system 204 transmits data related to object classification to the planning system 206.

[0060] In some examples, the planning system 206 receives destination-related data and generates data related to at least one route or trajectory along which a vehicle can travel towards the destination. In some embodiments, the planning system 206 periodically or continuously receives data from the sensing system 204 and updates the route or trajectory based on the data generated by the sensing system 204.

[0061] In some examples, control system 208 receives data associated with at least one trajectory from planning system 206, and control system 208 controls the operation of the vehicle. In some embodiments, control system 208 includes steering control system 208a and powertrain control system 208b. Control system 208 can control the operation of steering control system 208a and powertrain control system 208b according to the received trajectory. In some embodiments, powertrain control system 208b receives control signals from control system 208 to start, stop, accelerate, decelerate, turn left, turn right, or perform similar operations on the vehicle. Steering control system 208a is configured to receive control signals from control system 208 to turn one or more wheels of the vehicle. In some examples, when the trajectory includes a left turn, control system 208 transmits control signals to cause steering control system 208a to adjust the direction.

[0062] Figure 3 shows a schematic diagram of an exemplary device 300 for lidar.

[0063] In some examples, transmitter 310 emits first linearly polarized light as a transmitted beam. The first linearly polarized light is collimated into parallel light by transceiver lens 312 and then split by polarizing beam splitter 350 (e.g., transmitted or reflected). Upon passing through phase modulator 360, the first linearly polarized light becomes first circularly polarized light (e.g., left-handed or right-handed circularly polarized light), and is then transmitted to the object via first reflector 331, second reflector 332, and viewing window 340. When the first circularly polarized light is reflected by the object, its rotation direction is reversed, for example, from left-handed to right-handed or from right-handed to left-handed, causing the received beam to include second circularly polarized light. The received beam returns along the same path through the aforementioned optical system, and after passing through phase modulator 360, the second circularly polarized light becomes second linearly polarized light. When the second linearly polarized light passes through the polarization beam splitter 350, it will be transmitted along a receiving optical path that is different from the transmitting optical path between the transmitter 310 and the polarization beam splitter 350 (e.g., reflected or transmitted), and will be focused onto the receiver 320 by the receiving lens 322.

[0064] In the exemplary device 300 described above, the emitted and received beams pass through a mirror in the form of circularly polarized light. The mirror may exhibit a depolarization effect. Referring to Figure 4, a schematic diagram of the depolarization effect is shown. After passing through the mirror, the polarization state of the circularly polarized light may be affected; for example, the circularly polarized light may become elliptically polarized light. After passing through the phase modulator 360, the elliptically polarized light will not completely become linearly polarized light in the desired direction, but will instead become partially first linearly polarized light and partially second linearly polarized light. The first linearly polarized light cannot pass through the polarization beam splitter 350 and enter the receiving optical path between the polarization beam splitter 350 and the receiver 320, resulting in a loss of receiving efficiency in the device 300. Optical components exhibiting a depolarization effect can be equivalently considered as a waveplate (e.g., a 1 / 12 waveplate or a 1 / 8 waveplate, etc.), which disrupts the original polarization path.

[0065] According to some embodiments of this disclosure, an optical transceiver assembly for a lidar is provided. The optical transceiver assembly includes a transmitter, a receiver, a polarization beam splitter, a phase modulator, a window, and one or more optical components. The transmitter can emit a light beam having a first polarization state. The receiver can receive the echo generated after the light beam is reflected from an object. The echo received by the receiver has a second polarization state. The polarization direction of the first polarization state is different from the polarization direction of the second polarization state. The polarization beam splitter can change the direction of the light beam or the echo. The phase modulator can modulate the phase of the light beam and the echo. The light beam is transmitted to the lidar's field of view via the window, and the echo enters the lidar's interior via the window. The optical components may include one or more optical components. The phase modulator is located in the optical path between one or more optical components and the window. For example, the light beam passes sequentially through the optical component, the phase modulator, and the window. For example, the echo passes sequentially through the window, the phase modulator, and the optical component.

[0066] Referring to Figure 5, a schematic block diagram of an optical transceiver assembly 500 for a lidar, consistent with some embodiments of this disclosure, is shown. The optical transceiver assembly 500 includes a transmitter 510, a receiver 520, a polarization beam splitter 530, a phase modulator 540, one or more optics 550, and a window 560.

[0067] Emitter 510 can emit a light beam. Emitter 510 may include a laser or an array of lasers for emitting the light beam. For example, the laser array may include at least one of a one-dimensional array or a two-dimensional array. For example, multiple columns of lasers in the laser array may be aligned, or adjacent columns of lasers may have an offset. In some embodiments, emitter 510 may employ a laser emitting circuit or various types of lasers, including but not limited to VCSELs, EELs, etc. In some embodiments, emitter 510 may include a linearly polarized laser, such as an EEL laser or a linearly polarized VCSEL laser, to emit a light beam having a first polarization state.

[0068] Receiver 520 can receive the echo generated after a light beam is reflected by an object. Receiver 520 may include a detector or detector array for receiving the echo. For example, the detector array may include at least one of a one-dimensional array or a two-dimensional array. For example, multiple rows of detectors in the detector array may be aligned, or adjacent rows of detectors may have an offset. Receiver 520 may employ a photodetector circuit or various types of detectors, including but not limited to SPAD, APD, SiPM, etc. In some embodiments, the echo may have a second polarization state. The polarization direction of the first polarization state is different from the polarization direction of the second polarization state. In some embodiments, the polarization direction of the first polarization state may be orthogonal to the polarization direction of the second polarization state. Laser is an electromagnetic wave, and the vibration direction of its electric field can be defined as the polarization direction of the light beam. When the beam polarization direction is along a first direction, it can be called an S-polarization state. When the beam polarization direction is along a second direction perpendicular to the first direction, it can be called a P-polarization state. In some embodiments, the first polarization state may include one of the S-polarization state and the P-polarization state, while the second polarization state may include the other of the S-polarization state and the P-polarization state.

[0069] The polarization beam splitter 530 can change the direction of a beam or echo. In some embodiments, the polarization beam splitter 530 can reflect a beam with a first polarization state and transmit an echo with a second polarization state. In other embodiments, the polarization beam splitter 530 can transmit a beam with a first polarization state and reflect an echo with a second polarization state.

[0070] Phase modulator 540 can modulate the phase of the beam and the echo. In some embodiments, phase modulator 540 may include at least one of a quarter-wave plate, a Faraday rotator, or a liquid crystal polymer. Phase modulator 540 can convert first linearly polarized light into first circularly polarized light and convert second circularly polarized light into second linearly polarized light. For example, the first linearly polarized light may be orthogonal to the second linearly polarized light, and the rotation direction of the first circularly polarized light may be opposite to the rotation direction of the second circularly polarized light. For example, phase modulator 540 can convert P-polarized light into left-handed circularly polarized light and right-handed circularly polarized light into S-polarized light.

[0071] In some examples, one or more optical elements 550 can modulate at least one of the beam and the echo. Optical element 550 may include one or more optical components. For example, one or more optical elements 550 may include at least one of a scanner, lens, mirror, filter, beam splitter, aperture, homogenizer, prism, and grating. In some embodiments, one or more optical elements 550 may include at least one of refractive, reflective, transmissive, and diffractive optical elements. For example, refractive optics may include lenses or prisms. For example, reflective optics may include mirrors or scanners. For example, transmissive optics may include waveplates, filters, or apertures. For example, diffractive optics include homogenizers or gratings. In some examples, one or more optical elements 550 may be located in the optical path between phase modulator 540 and polarization beam splitter 530. In some examples, one or more optical elements 550 may be located in the optical path between polarization beam splitter 530 and receiver 520. In some examples, one or more optical components 550 may be located in the optical path between the transmitter 510 and the polarizing beam splitter 530.

[0072] In some embodiments, the transmitter 510, receiver 520, polarization beam splitter 530, phase modulator 540, optics 550, and window 560 may be substantially located in the same plane, for example, in the xz plane. In some instances, any two of the transmitter 510, receiver 520, polarization beam splitter 530, phase modulator 540, optics 550, and window 560 may be partially or completely offset in the y-direction (perpendicular to the xz plane).

[0073] A lidar system may include a window 560 to protect internal components such as optics, transmitters, and receivers. A light beam is transmitted to the outside of the lidar system via the window 560. The echo enters the lidar system via the window. In some embodiments, the window 560 may also filter out interference from noisy light signals, improving the lidar's detection performance. In some embodiments, the material of the window 560 may include glass or PC. In some embodiments, the window 560 may be part of a car windshield. In some embodiments, the window 560 may be formed as a lens.

[0074] In some embodiments, the phase modulator 540 may be located between one or more optical elements 550 and the window 560 in the optical path. A light beam with a first polarization state can maintain its first polarization state in the transmitted optical path between the transmitter 510 and the phase modulator 540, without being depolarized by one or more optical elements 550. After passing through the phase modulator 540, the light beam with the first polarization state becomes circularly polarized light (e.g., left-handed or right-handed circularly polarized light). The circularly polarized light forms an echo after being reflected by an object. The polarization state of the echo is reversed, for example, from left-handed to right-handed or from right-handed to left-handed. After passing through the phase modulator 540, the polarization state of the echo with the reversed polarization state is a second polarization state. The echo with the second polarization state can maintain its second polarization state in the received optical path between the phase modulator 540 and the receiver 520, without being depolarized by one or more optical elements 550. Some embodiments can improve the receiving efficiency of the optical transceiver assembly 500, which helps to improve the detection performance of the lidar.

[0075] In some embodiments, the phase modulator 540 may be located between the refractive optics and the window 560. In some embodiments, the phase modulator 540 may be located between the reflective optics and the window 560. In some embodiments, the phase modulator 540 may be located between the transmissive optics and the window 560. In some embodiments, the phase modulator 540 may be located between the diffractive optics and the window 560.

[0076] In some embodiments, the number of refractive optical elements between the phase modulator 540 and the window 560 may be less than a preset value. In some embodiments, the number of reflective optical elements between the phase modulator 540 and the window 560 may be less than a preset value. In some embodiments, the number of transmissive optical elements between the phase modulator 540 and the window 560 may be less than a preset value. In some embodiments, the number of diffractive optical elements between the phase modulator 540 and the window 560 may be less than a preset value. For example, the preset value may include 5, 4, 3, 2, or 1.

[0077] In some embodiments, one or more of the following optical elements may not exist between the phase modulator 540 and the window 560: a refractive optical element, a reflective optical element, a transmissive optical element, and a diffractive optical element.

[0078] In some embodiments, the distance between the phase modulator 540 and the window 560 may be less than the distance between the optics 550 and the window 560. In some embodiments, the phase modulator 540 may be located between the window 560 and the optics 550 along a direction perpendicular to the window surface. In some embodiments, the transmitter 510 and the receiver 520 may be located on the same side of the phase modulator 540. For example, the transmitter 510 and the receiver 520 may be located on the side of the phase modulator 540 away from the window 560.

[0079] Figure 6 shows a schematic block diagram of a phase modulator consistent with some embodiments of this disclosure.

[0080] In some embodiments, the phase modulator 640 includes a first region A1. A light beam from a transmitter (not shown) includes a first beam. The first beam is incident on the first region A1 of the phase modulator 640. The phase modulator 640 can be configured such that a first angle between the first beam and the fast axis direction of the first region A1 is within a first preset range. For example, the first preset range may include a range between 40° and 50°. For example, the first preset range may include a range between 43° and 46°. For example, the first angle may be 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, or 50°. Thus, after passing through the first region A1 of the phase modulator 640, the first beam having a first polarization state can become circularly polarized light.

[0081] In some embodiments, the phase modulator 640 may further include a second region A2. The light beam from the transmitter (not shown) may include a second light beam. The second light beam is incident on the second region A2 of the phase modulator 640. The phase modulator 640 may allow a second angle between the second light beam and the fast axis direction of the second region A2 to be within a first preset range. For example, the second angle may be 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, or 50°. Thus, after passing through the first region A1 of the phase modulator 640, the second light beam having a first polarization state may become circularly polarized light.

[0082] In some embodiments, when the first beam and the second beam are incident on the phase modulator 640 at different incident angles, the fast axis direction of the first region A1 may be different from the fast axis direction of the second region A2. This helps to ensure that the first angle between the polarization direction of the first beam and the fast axis of the phase modulator 640 (e.g., a quarter-wave plate) is substantially equal to the second angle between the polarization direction of the second beam and the fast axis of the phase modulator 640 (e.g., a quarter-wave plate).

[0083] In some embodiments, the first region A1 and the second region A2 may be adjacent. For example, the second region A2 may be located on one or both sides of the first region A1. For example, the second region A2 may be located around the first region A1. For example, the second region A2 may surround the first region A1. In some embodiments, the first region A1 may be circular, elliptical, rectangular, or other shapes. In some embodiments, the second region A2 may be an annular region.

[0084] In some embodiments, the first region A1 and the second region A2 may lie in the same plane. In some embodiments, the first region A1 and the second region A2 may lie in different planes. For example, in some embodiments, there may be an angle between the plane containing the first region A1 and the plane containing the second region A2. In some embodiments, the first region A1 and the second region A2 may have the same radius of curvature. For example, the first region A1 and the second region A2 may lie in different regions of the same surface. In some embodiments, the first region A1 and the second region A2 may have different radii of curvature.

[0085] In some embodiments, the phase modulator 640 may include multiple regions. The multiple regions have different fast axis orientations relative to each other. For example, the scanning range of a lidar may be divided into multiple regions, and correspondingly, the phase modulator 640 (e.g., a quarter-wave plate) may be divided into multiple regions, with different regions having different fast axis orientations.

[0086] For example, the phase modulator 640 (e.g., a quarter-wave plate) can be divided into multiple regions based on the angular resolution of the lidar in a first direction (e.g., the x-direction as shown in Figure 6), and different regions can have different fast axis directions. As another example, the phase modulator 640 (e.g., a quarter-wave plate) can be divided into multiple regions based on the angular resolution of the lidar in a second direction (e.g., the y-direction perpendicular to the xz plane), and different regions can have different fast axis directions.

[0087] In some embodiments, the phase modulator 640 includes a plurality of regions that can be distributed in an array along a first direction. In other embodiments, the phase modulator 640 includes a plurality of regions that can be distributed in an array along a second direction. In still other embodiments, the phase modulator 640 includes a plurality of regions that can be distributed in an array along both the first and second directions. Different regions may have different fast axis orientations.

[0088] In some embodiments, the phase modulator 640 may be a polymer waveplate. The polymer waveplate may include multiple regions. The polymer waveplate is advantageous because it allows the fast axis direction and delay of each region to be set and adjusted according to the polarization direction of the beam incident on that region.

[0089] In some embodiments, one or more optical components may include a scanner. The scanner may include a reflective surface. A phase modulator may be located between the scanner and the viewing window in the optical path. The scanner may change the exit direction of the light beam along a first direction. For example, the first direction is the x-direction.

[0090] In some embodiments, the scanner can change the emission direction of the light beam along a first direction and a second direction. The first direction and the second direction can be perpendicular to each other. For example, the second direction is the y-direction perpendicular to the xz-plane.

[0091] In some embodiments, the scanner may include one two-dimensional scanner or two one-dimensional scanners. For example, the scanner may include a rotating optical engine, a rotating mirror, a reciprocating oscillating mirror or galvanometer (e.g., a MEMS mirror, a Galvo mirror, etc.), and other components that can direct the laser beam to different locations in the environment (e.g., prisms, gratings, diffractive optical elements, etc.). For example, the two one-dimensional scanners may be of the same type or of different types.

[0092] Figure 7 shows a schematic block diagram of an optical transceiver assembly 700 for a lidar according to a second exemplary embodiment consistent with some embodiments of this disclosure. Several details of the second exemplary embodiment are similar to those of the first exemplary embodiment and will not be repeated here. The following mainly describes the differences of the second exemplary embodiment.

[0093] The optical transceiver assembly 700 may include a transmitter 710, a receiver 720, a polarization beam splitter 730, a phase modulator 740, one or more optical components, and a window 760.

[0094] The phase modulator 740 is located in the optical path between the polarization beam splitter 730 and the window 760, and is located between the optical component and the window 760.

[0095] Optionally, the optics may include a emitting optics 752. The emitting optics 752 may shape (e.g., collimate) the beam emitted by the emitter 710 and guide the beam to the polarization beam splitter 730.

[0096] Optionally, one or more optics of the optical transceiver assembly 700 may include receiving optics 754. Receiving optics 754 may transmit the echo to receiver 720. For example, receiving optics 754 may focus the echo onto a detector in receiver 720.

[0097] Optionally, the optical components may include a first reflector 755 or a first scanner 756. In some embodiments, the first reflector 755 may reflect the light beam to change the transmission direction of the light beam. In other embodiments, the first scanner 756 may change the exit direction of the light beam along one of a first direction (e.g., the x-direction) and a second direction (e.g., the y-direction perpendicular to the xz-plane).

[0098] Optionally, one or more optical components of the optical transceiver assembly 700 may further include a second scanner 758. The second scanner 758 may be located between the first scanner 756 and the phase modulator 740. The second scanner 758 may change the exit direction of the light beam along a first direction (e.g., the x-direction) and a second direction (e.g., the y-direction perpendicular to the xz-plane).

[0099] In some embodiments, a one-dimensional scanner or a two-dimensional scanner may include a reflective surface. A phase modulator may be disposed on the reflective surface of the scanner.

[0100] Figure 8 shows a schematic block diagram of an optical transceiver assembly 800 for a lidar according to a third exemplary embodiment consistent with some embodiments of this disclosure. Several details of the third exemplary embodiment are similar to those of the first or second exemplary embodiments, and will not be repeated here. The following mainly describes the differences of the third exemplary embodiment.

[0101] The optical transceiver assembly 800 may include a transmitter 810, a receiver 820, a polarization beam splitter 830, a phase modulator 840, optional transmitting optics 852, optional receiving optics 854, optional first reflector 855 or first scanner 856, second scanner 858, and window 860.

[0102] In some embodiments, the second scanner 858 may include a reflective surface. A phase modulator 840 may be disposed on the reflective surface of the second scanner 858. For example, the phase modulator 840 may be a phase retardation film formed on the reflective surface of the second scanner 858. The phase retardation film may be formed using any of the following processes: coating (e.g., spin coating, blade coating, or spray coating), physical vapor deposition (e.g., evaporation or magnetron sputtering), chemical vapor deposition, hot pressing, or nanoimprinting. For example, the shape of the phase modulator 840 may be substantially the same as the shape of the reflective surface of the second scanner 858. For example, the size of the phase modulator 840 may be substantially the same as the size of the reflective surface of the second scanner 858.

[0103] In some embodiments, the phase modulator 840 may include a liquid crystal polymer. Liquid crystal polymers are less expensive and can be better formed on the reflective surface of the second scanner 858.

[0104] In some embodiments, the phase modulator 840 may include a quartz material.

[0105] Figure 9 shows a schematic block diagram of an optical transceiver assembly 900 for a lidar according to a fourth exemplary embodiment consistent with some embodiments of this disclosure. Several details of the fourth exemplary embodiment are similar to those of the first, second, or third exemplary embodiments, and will not be repeated here. The following mainly describes the differences of the fourth exemplary embodiment.

[0106] The optical transceiver assembly 900 may include a transmitter 910, a receiver 920, a polarization beam splitter 930, a phase modulator 940, optional transmitting optics 952, optional receiving optics 954, optional first reflector 955 or first scanner 956, optional second scanner 958, and a window 960.

[0107] Phase modulator 940 can be disposed on the surface of window 960. For example, phase modulator 940 can be disposed on the inner or outer surface of window 960. For example, phase modulator 940 can be a phase retardation film formed on the surface of window 960. The phase retardation film can be formed using any of the following processes: coating (e.g., spin coating, blade coating, or spray coating), physical vapor deposition (e.g., evaporation or magnetron sputtering), chemical vapor deposition, hot pressing, or nanoimprinting. For example, the shape of phase modulator 940 can be substantially the same as the shape of window 960. For example, the size of phase modulator 940 can be substantially the same as the size of window 960. For example, phase modulator 940 can cover the entire window 960 or a portion of the window 960. For example, phase modulator 940 can be located in the area of ​​window 960 near the second scanner 958.

[0108] In some embodiments, the phase modulator 940 may include a liquid crystal polymer. Liquid crystal polymers are less expensive and can be better formed on the surface of the window 960.

[0109] In some embodiments, the phase modulator 940 may include a quartz material.

[0110] Figure 10 shows a schematic block diagram of a phase modulator consistent with some embodiments of the present disclosure.

[0111] In some embodiments, phase modulator 1040 may include a first region B1. A light beam from a transmitter (not shown) may include a first beam. The first beam is incident on the first region B1 of phase modulator 1040. Phase modulator 1040 may be a curved phase modulator such that the first beam is incident substantially perpendicularly on the first region B1. In this document, the term "first beam incident substantially perpendicularly on the first region" is intended to indicate that the angle of incidence of the first beam on the first region is between 80° and 100°.

[0112] In some embodiments, the phase modulator 1040 may further include a second region B2. The beam from the transmitter (not shown) may also include a second beam. The second beam is incident on the second region B2 of the phase modulator 1040. The phase modulator 1040 may be a curved phase modulator such that the second beam is incident substantially perpendicularly on the second region B2. This helps to ensure that beams from the transmitter are all incident perpendicularly on the phase modulator 1040. In this document, the term "the second beam is incident substantially perpendicularly on the second region" is intended to mean that the angle of incidence of the second beam on the second region is between 80° and 100°.

[0113] In some embodiments, the phase modulator 1040 may have an arc surface. The center of the arc surface may substantially coincide with the rotation center of the scanner.

[0114] In some embodiments, the phase modulator 1040 may have a spherical surface. The center of the sphere substantially coincides with the rotation center of the scanner.

[0115] In some embodiments, the radii of curvature of the first region B1 and the second region B2 may be substantially the same. In some embodiments, the radii of curvature of the first region B1 and the second region B2 may be different.

[0116] Figure 11 shows a schematic block diagram of an optical transceiver assembly 1100 for a lidar according to a fifth exemplary embodiment consistent with some embodiments of this disclosure. Several details of the fifth exemplary embodiment are similar to those of the first, second, third, or fourth exemplary embodiments, and will not be repeated here. The following mainly describes the differences of the fifth exemplary embodiment.

[0117] The optical transceiver assembly 1100 may include a transmitter 1110, a receiver 1120, a polarization beam splitter 1130, a phase modulator 1140, optional transmitting optics 1152, optional receiving optics 1154, optional first reflector 1155 or first scanner 1156, optional second scanner 1158, and a window 1160.

[0118] Phase modulator 1140 may be a curved phase modulator. In some embodiments, window 1160 may be a curved window. Phase modulator 1140 may be disposed on the surface of window 1160. For example, phase modulator 1140 may be disposed on the inner or outer surface of window 1160. For example, phase modulator 1140 may be a phase retardation film formed on the surface of window 1160. The phase retardation film may be formed using any of the following processes: coating (e.g., spin coating, blade coating, or spray coating), physical vapor deposition (e.g., evaporation or magnetron sputtering), chemical vapor deposition, hot pressing, or nanoimprinting.

[0119] In some embodiments, the phase modulator 1140 may have an arcuate surface, and the window 1160 may be a window with an arcuate surface. The radius of the arcuate surface of the phase modulator 1140 may be substantially the same as the radius of the arcuate surface of the window.

[0120] In some embodiments, the phase modulator 1140 may have a spherical surface, and the window 1160 may be a window with a spherical surface. The radius of the spherical surface of the phase modulator 1140 may be substantially the same as the radius of the spherical surface of the window. In some embodiments, the phase modulator 1140 may include a liquid crystal polymer. Liquid crystal polymers are less expensive and can be better formed on the surface of the window 1160.

[0121] In some embodiments, the phase modulator 1140 may include a quartz material.

[0122] In some embodiments, one or more optical elements may include optical surfaces. For example, an optical surface may include at least one of a refractive surface, a reflective surface, and a diffractive surface. Optical elements may include isotropic or anisotropic optical elements. An isotropic optical element has the same refractive index in different directions with respect to the light beam. An anisotropic optical element has different refractive indices in different directions with respect to the light beam. In some embodiments, the angle between the fast axis direction of the optical surface of the anisotropic optical element and the light beam incident on the optical surface may be within a second preset range. For example, the second preset range may include a range between -15° and 15° or a range between 75° and 105°. For example, the angle between the fast axis direction of the optical surface of an anisotropic optical component and the light beam incident on the optical surface can be -15°, -14°, -13°, -12°, -11°, -10°, -9°, -8°, -7°, -6°, -5°, -4°, -3°, -2°, -1°, 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, or 15°. For example, the angle between the fast axis direction of the optical surface of an anisotropic optical element and the light beam incident on the optical surface can be 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, 96°, 97°, 98°, 99°, 100°, 101°, 102°, 103°, 104°, or 105°. In this way, the anisotropic optical element essentially does not change the polarization state of the light beam. If the angle between the fast axis direction of the optical surface of the anisotropic optical element and the light beam incident on the optical surface is 0° or 90°, then the anisotropic optical element does not change the polarization state of the light beam at all. When the angle between the fast axis direction of the optical surface of an anisotropic optical element and the beam incident on the optical surface is within 0°±15° or 90°±15°, the anisotropic optical element slightly alters the polarization state of the beam.

[0123] In some embodiments, the phase modulator can be positioned after all the optics of the optical transceiver assembly and in front of the window in the direction of propagation of the beam emitted by the transmitter. For example, there may be no optics between the phase modulator and the window.

[0124] In some embodiments, the transmitter may include a laser. The laser may emit linearly polarized light having a first polarization state.

[0125] In other embodiments, the transmitter may include a laser and a polarizer. The laser can emit laser light. The polarizer can convert the laser light into linearly polarized light with a first polarization state.

[0126] In some embodiments, at least two of the transmitter, receiver, and polarization beam splitter are integrated into a transceiver chip.

[0127] Figure 12 shows a schematic block diagram of an optical transceiver assembly 1200 for a lidar according to a sixth exemplary embodiment consistent with some embodiments of this disclosure. Several details of the sixth exemplary embodiment are similar to those of the first, second, third, fourth, or fifth exemplary embodiments, and will not be repeated here. The following mainly describes the differences of the sixth exemplary embodiment.

[0128] The optical transceiver assembly 1200 may include a transmitter 1210, a receiver 1220, a polarization beam splitter 1230, a phase modulator 1240, optional transceiver optics 1253, optional first reflector 1255 or first scanner 1256, optional second scanner 1258, and a window 1260.

[0129] The optical transceiver assembly 1200 may further include a transceiver chip 12. In some embodiments, at least one of the transmitter 1210, receiver 1220, and polarization beam splitter 1230 may be disposed on the transceiver chip 12. For example, as shown in FIG12, the transmitter 1210, receiver 1220, and polarization beam splitter 1230 are disposed on the transceiver chip 12. In some examples, the transmitter 1210 and polarization beam splitter 1230 may be disposed on the transceiver chip 12. In some examples, the receiver 1220 may be disposed on the end face of the transceiver chip 12. In some examples, the receiver 1220 and polarization beam splitter 1230 may be disposed on the transceiver chip 12. In some examples, the transmitter 1210 may be disposed on the end face of the transceiver chip 12 or connected to the transceiver chip 12 via optical fiber, spatial optical element, other chip, etc.

[0130] Optionally, the optical transceiver assembly 1200 may include transceiver optics 1253. Transceiver optics 1253 can collimate the light beam emitted by the transmitter 1210 and transmit the echo to the receiver 1220. Transceiver optics 1253 may include one or more optical devices such as lenses / lens groups, mirrors, filters, beam splitters, apertures, and homogenizers.

[0131] According to another exemplary embodiment of this disclosure, a lidar is also provided.

[0132] The lidar may include the optical transceiver assembly 500, 700, 800, 900, 1100, or 1200 described above. The lidar may also include a controller (e.g., as part of the control and processing system 130). The controller may control the transmitter to emit a beam and calculate at least one of the distance to an object and its reflectivity based on the echo received by the receiver.

[0133] According to another exemplary embodiment of this disclosure, a terminal device is also provided. The terminal device may include the lidar described above. In some embodiments, the terminal device includes a vehicle, robot, drone, etc.

[0134] This concludes the description of an optical transceiver assembly, a lidar, and a terminal device for lidar according to the present disclosure. The optical transceiver assembly for lidar of the present disclosure helps to solve the problem of depolarization of polarized beams after passing through optics in polarized lidar by placing a phase modulator after one or more optical components.

[0135] It should be understood that the above description is illustrative and not restrictive. For example, the above embodiments (and / or aspects thereof) can be used in combination with each other. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of the various embodiments of this disclosure without departing from the scope of this disclosure. While the dimensions and types of materials described herein are used to define parameters of the various embodiments of this disclosure, the embodiments are not intended to be restrictive but are exemplary. Many other embodiments will become apparent to those skilled in the art upon reading the above description. Therefore, the scope of the various embodiments of this disclosure should be determined by reference to the appended claims and the full scope of their equivalents.

Claims

1. An optical transceiver assembly for lidar, comprising: A transmitter configured to emit a light beam having a first polarization state; A receiver configured to receive an echo generated after the light beam is reflected by an object, wherein the echo received by the receiver has a second polarization state, the polarization direction of the first polarization state being different from the polarization direction of the second polarization state; A polarizing beam splitter configured to change the direction of the beam or the echo; A phase modulator configured to modulate the phase of the beam and the echo; A viewing window through which the light beam is transmitted to the outside of the lidar and the echo enters the interior of the lidar through the viewing window; as well as One or more optical elements, wherein the phase modulator is located in the optical path between the one or more optical elements and the window.

2. The optical transceiver module of claim 1, wherein the optical subassembly is mounted on the substrate by a solder joint. The one or more optical components include at least one of a scanner, lens, mirror, filter, aperture, homogenizer, prism, and grating.

3. The optical transceiver module of claim 1, wherein the optical subassembly is mounted on the substrate by a solder joint. The phase modulator includes at least one of a quarter-wave plate, a Faraday rotator, or a liquid crystal polymer.

4. The optical transceiver module of claim 1, wherein the optical subassembly is mounted on the substrate by a solder joint. The phase modulator is located in the optical path between the polarization beam splitter and the window.

5. The optical transceiver module of claim 1, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The phase modulator is disposed on the surface of the window.

6. The optical transceiver module of claim 1, wherein the optical subassembly is configured to be mounted on a printed circuit board. The phase modulator includes a first region and a second region and satisfies: The fast axis direction of the first region is different from that of the second region.

7. The optical transceiver module of claim 6, wherein the optical subassembly is mounted on the circuit board by a plurality of solder balls. The light beam includes a first light beam incident on the first region and a second light beam incident on the second region, wherein the phase modulator is configured such that a first angle between the first light beam and the fast axis direction of the first region is within a first preset range, and a second angle between the second light beam and the fast axis direction of the second region is within the first preset range.

8. The optical transceiver module of claim 7, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The first preset range includes a range between 40° and 50°.

9. The optical transceiver module of claim 1, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The phase modulator includes a first region and a second region, the beam includes a first beam incident on the first region and a second beam incident on the second region, wherein the phase modulator is configured as a curved phase modulator such that the first beam is incident substantially perpendicularly on the first region and the second beam is incident substantially perpendicularly on the second region.

10. The optical transceiver module of claim 1, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The optical component includes a scanner, and the phase modulator is located in the optical path between the scanner and the window.

11. The optical transceiver module of claim 10, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The scanner includes a reflective surface, and the phase modulator is disposed on the reflective surface of the scanner.

12. The optical transceiver module of claim 10, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The scanner is configured to change the emission direction of the beam along a first direction; or The scanner is configured to change the emission direction of the beam along a first direction and a second direction, wherein the first direction and the second direction are perpendicular to each other.

13. The optical transceiver module of claim 10, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The scanner may include one two-dimensional scanner or two one-dimensional scanners.

14. The optical transceiver package of any one of claims 1-13, wherein, The one or more optical elements include an optical surface, and the angle between the fast axis direction of the optical surface and the light beam incident on the optical surface is within a second preset range.

15. The optical transceiver module of claim 14, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The second preset range includes a range between -15° and 15° or a range between 75° and 105°.

16. The optical transceiver module of claim 14, wherein the optical subassembly is configured to be mounted on a printed circuit board (PCB) of the optical transceiver module. The optical surface includes at least one of a refractive surface, a reflective surface, and a diffractive surface.

17. The optical transceiver package of any one of claims 1-13, wherein the optical transceiver package is configured to be mounted to a circuit board using a surface mount technology. The transmitter includes a laser configured to emit linearly polarized light having the first polarization state.

18. The optical transceiver package of any one of claims 1-13, wherein, At least two of the transmitter, the receiver, and the polarization beam splitter are integrated into a transceiver chip.

19. A lidar, comprising: The optical transceiver assembly as described in any one of claims 1-18; as well as The controller is configured as follows: Control the transmitter to emit the beam; and Based on the echo received by the receiver, at least one of the object's distance and reflectivity is calculated.

20. A terminal device comprising the lidar as described in claim 19.

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