LIDAR sensor system

Abstract

A LiDAR (Light Detection and Ranging) system for vehicles includes a transmitter, a receiver, one or more scanning optics, and an optical module. The transmitter is configured to output a transmitted light beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The optical module is configured to receive the transmitted light beam and provide it to the one or more scanning optics, receive a reflected light beam from an object, split the reflected light beam into at least a first component and a second component, and direct the first component to the first receiving grating coupler and the second component to the second receiving grating coupler.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Patent Application No. 17 / 886,398, filed August 11, 2022. The entire disclosure of U.S. Patent Application No. 17 / 886,398 is incorporated herein by reference. Background Technology

[0003] Optical range detection using lasers (often referred to by the mnemonic LIDAR (which stands for "light detection and ranging"), and sometimes also called "laser radar (RADAR)") is used in a variety of applications, including imaging and collision avoidance. Compared to traditional microwave ranging systems, such as radio wave detection and ranging (RADAR), LIDAR provides finer-scale range resolution with a smaller beam size. Summary of the Invention

[0004] At least one aspect relates to an optical detection and ranging (LIDAR) system, such as a LIDAR sensor system for a vehicle. The LIDAR system includes a transmitter configured to output an emitted light beam. The LIDAR system includes a receiver. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The LIDAR system includes one or more scanning optics. The LIDAR system includes a circulator. The circulator is configured to receive the emitted light beam and direct the emitted light beam to one or more scanning optics, receive a returned light beam reflected from an object, split the returned light beam into at least a first component and a second component, and direct the first component to the first receiving grating coupler and the second component to the second receiving grating coupler.

[0005] At least one aspect relates to an autonomous vehicle control system. The autonomous vehicle control system includes a transmitter, a receiver, one or more scanning optics, a circulator, and one or more processors. The transmitter is configured to output a transmitted light beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The circulator is configured to receive the transmitted light beam and direct it to one or more scanning optics, receive a returned light beam reflected from an object, split the returned light beam into at least a first component and a second component, and direct the first component to the first receiving grating coupler and the second component to the second receiving grating coupler. The one or more processors are configured to determine at least one of the range to an object or the velocity of an object based on the first component and the second component, and to control the operation of the autonomous vehicle in response to at least one of the range or velocity.

[0006] At least one aspect relates to an autonomous vehicle. The autonomous vehicle includes a LIDAR system comprising a transmitter, a receiver, one or more scanning optics, and a circulator. The transmitter is configured to output a transmitted light beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The circulator is configured to receive the transmitted light beam and direct it to one or more scanning optics, receive a returned light beam reflected from an object, split the returned light beam into at least a first component and a second component, and direct the first component to the first receiving grating coupler and the second component to the second receiving grating coupler. The autonomous vehicle includes a steering system, a braking system, and a vehicle controller. The vehicle controller includes one or more processors configured to determine at least one of the distance to an object or the velocity of an object based on the first and second components, and to control the operation of the autonomous vehicle in response to at least one of the distance or velocity.

[0007] At least one aspect relates to a LIDAR sensor system. The LIDAR sensor system includes a transmitter, a receiver, and an optical module. The transmitter is configured to output an emitted beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The optical module is configured to receive a returned beam of the emitted beam reflected by an object, and to provide a first component of the returned beam to the first receiving grating coupler and a second component of the returned beam to the second receiving grating coupler.

[0008] In some embodiments, the emitted beam is polarized, and the optical module is further configured to rotate the polarization of the emitted beam such that a first component of the returned beam is polarized such that the polarization of the first component corresponds to the polarization of the emitted beam, and to polarize a second component of the returned beam such that the polarization of the second component is orthogonal to the polarization of the emitted beam.

[0009] In some implementations, a LIDAR sensor system includes one or more scanning optics configured to receive an emitted beam from an optical module and output an emitted beam.

[0010] In some implementations, the LIDAR sensor system includes a chip made of III-V semiconductor material, wherein the transmitter and receiver are located on the chip.

[0011] In some implementations, the transmitter includes at least one emission grating coupler.

[0012] In some implementations, the first receiving grating coupler is a structure formed by etching on the chip or depositing material on the chip.

[0013] In some embodiments, the optical module includes a first half-wave plate located between the transmitter and one or more scanning optics, a shifter located between the half-wave plate and one or more scanning optics, and a second half-wave plate located between the shifter and one or more scanning optics.

[0014] In some implementations, the optical module includes a collimator configured to collimate the emitted beam.

[0015] In some implementations, the LIDAR sensor system includes at least one mixer configured to output a signal based on at least one of a local oscillator signal and a first component of the returned beam or a second component of the returned beam.

[0016] In some implementations, the distance between the first receiving grating coupler and the transmitter is a first distance corresponding to a time delay associated with the target range for detecting an object, and the distance between the second receiving grating coupler and the transmitter is a second distance corresponding to the time delay and the displacement of the second component relative to the first component through the optical module.

[0017] In some embodiments, a first receiving grating coupler receives at least about 50 percent of a first component of the returned beam, and a second receiving grating coupler receives at least about 50 percent of a second component of the returned beam.

[0018] In some implementations, the optical module includes components made of... A displacement device is fabricated with a thickness between approximately 0.53 mm and approximately 0.65 mm. The displacement device can be positioned between the transmitter and one or more scanning optics and is configured to shift the second component of the returned beam between approximately 18 micrometers and approximately 22 micrometers.

[0019] In some implementations, the transmitter is located on the chip and configured to output the emitted beam at an angle to the chip plane.

[0020] At least one aspect relates to an autonomous vehicle control system comprising a transmitter, a receiver, an optical module, and one or more processors. The transmitter is configured to output a transmitted light beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The optical module is configured to receive a reflected light beam from an object, and to direct a first component of the reflected light beam to the first receiving grating coupler and a second component of the reflected light beam to the second receiving grating coupler. The one or more processors are configured to determine at least one of the range to an object or the velocity of an object based on the first and second components, and to control the operation of the autonomous vehicle in response to at least one of the range or velocity.

[0021] In some implementations, the autonomous vehicle control system includes a modulator configured to apply at least one of frequency modulation or phase modulation to a beam output by a transmitter as an emitted beam.

[0022] In some embodiments, the emitted beam is polarized, and the circulator is further configured to rotate the polarization of the emitted beam such that a first component of the returned beam is polarized such that the polarization of the first component corresponds to the polarization of the emitted beam, and to polarize a second component of the returned beam such that the polarization of the second component is orthogonal to the polarization of the emitted beam.

[0023] In some implementations, the distance between the first receiving grating coupler and the transmitter is a first distance corresponding to a time delay associated with the target range for detecting an object, and the distance between the second receiving grating coupler and the transmitter is a second distance corresponding to the time delay and the displacement of the second component relative to the first component through the optical module.

[0024] At least one aspect relates to an autonomous vehicle comprising a LIDAR sensor system, a steering system, a braking system, and a vehicle controller. The LIDAR sensor system includes a transmitting grating coupler configured to output an emitted light beam, a first receiving grating coupler, a second receiving grating coupler, and an optical module configured to receive a reflected light beam from an object, and to direct a first component of the reflected light beam to the first receiving grating coupler and a second component of the reflected light beam to the second receiving grating coupler. The vehicle controller includes one or more processors configured to use the first and second components to determine at least one of a distance to an object or a velocity of the object, and to control the operation of at least one of the steering system or the braking system in response to at least one of the distance or velocity.

[0025] In some implementations, a LIDAR sensor system includes one or more scanning optics configured to receive an emitted beam from an optical module and output an emitted beam.

[0026] In some implementations, the LIDAR sensor system includes a chip made of III-V semiconductor material, wherein the transmitter and receiver are located on the chip.

[0027] Those skilled in the art will understand that the invention is illustrative only and is not intended to be limiting in any way. Any feature described herein may be used in conjunction with any other feature, and any subset of such features may be combined according to various embodiments. Other aspects, inventive features, and advantages of the apparatus and / or process described herein (defined only by the claims) will become apparent from the detailed description set forth herein and taken in conjunction with the accompanying drawings. Attached Figure Description

[0028] In the accompanying drawings, embodiments are shown by way of example and not limitation, wherein the same reference numerals denote similar elements, and wherein:

[0029] Figure 1 This is a block diagram illustrating an example of the system environment for an autonomous vehicle.

[0030] Figure 2 This is a block diagram illustrating an example of the system environment for an autonomous commercial truck.

[0031] Figure 3 This is a block diagram illustrating an example of the system environment for an autonomous commercial truck.

[0032] Figure 4 This is a block diagram illustrating an example of the system environment for an autonomous commercial truck.

[0033] Figure 5 This is a block diagram of an example of a LIDAR sensor system;

[0034] Figure 6 This is a block diagram of an example optical module of a LIDAR sensor system;

[0035] Figure 7 This is a block diagram of an example of a LIDAR sensor system;

[0036] Figure 8 This is a block diagram illustrating an example of the system's optical components;

[0037] Figure 9 It includes Figure 8 A block diagram of an example LIDAR sensor system with optical components;

[0038] Figure 10 This is a block diagram illustrating an example of the system's optical components;

[0039] Figure 11 It includes Figure 10 A block diagram of an example LIDAR sensor system with optical components;

[0040] Figure 12 This is a block diagram illustrating an example of the system's optical components;

[0041] Figure 13 This is a block diagram illustrating an example of the system's optical components;

[0042] Figure 14 This is a block diagram illustrating an example of the system's optical components;

[0043] Figure 15 It includes Figure 14 A block diagram of an example LIDAR sensor system with optical components;

[0044] Figure 16 This is a block diagram illustrating an example of the system's optical components; and

[0045] Figure 17 This is a block diagram of a looper example. Detailed Implementation

[0046] A LIDAR sensor system can generate and emit a beam of light, which an object can reflect or otherwise scatter into a returning beam corresponding to the emitted beam. The LIDAR sensor system can receive the returning beam and process it, or its characteristics, to determine parameters about the object, such as its range and velocity. The LIDAR sensor system can apply various frequency or phase modulations to the emitted beam, which can help correlate the returning beam with the emitted beam to determine parameters about the object.

[0047] A LIDAR sensor system may include a transmitter, a receiver, one or more scanning optics, and a circulator. The transmitter is configured to output an emitted beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The circulator is configured to receive the emitted beam and direct it to one or more scanning optics, receive a return beam reflected from an object, split the return beam into at least a first component and a second component, and direct the first component to the first receiving grating coupler and the second component to the second receiving grating coupler. The one or more scanning optics may include mirrors to output the emitted beam, which may be scanned across the field of view to be reflected or otherwise scattered by an object as a return beam capable of determining distance, velocity, and Doppler information about an object, such as for controlling the operation of an autonomous vehicle.

[0048] The systems and methods according to this disclosure enable LIDAR sensor systems in which the circulator design and receiver grating coupler are assembled along the mechanical scanning axis rather than along the transmitter array axis. This arrangement simplifies optical design. For example, the circulator optics can be tilted to reduce back reflections. The tilt of the circulator optics can affect the displacement amplitude of the returned beam without affecting its direction. Therefore, the radiation from the grating coupler can have an angle greater than the tilt angle of the circulator optics, which improves processing efficiency. For example, this allows the circulator optics to be mounted parallel to the integrated chip containing the transmitter and receiver. However, the advantages of the aforementioned integrated chip are not limited to autonomous vehicles. They are advantageous for any type of vehicle equipped with LIDAR sensors.

[0049] 1. System environment of autonomous vehicles

[0050] Figure 1This is a block diagram illustrating an example of the system environment of an autonomous vehicle according to some implementation methods. Figure 1 An example autonomous vehicle 100 is depicted, in which various technologies disclosed herein can be implemented. For example, vehicle 100 may include a powertrain 102 comprising a prime mover 104 powered by energy source 106 and capable of supplying power to a transmission assembly 108; and a control system 110 comprising steering control 112, powertrain control 114, and braking control 116. Vehicle 100 can be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or goods and capable of operating in a variety of environments. The aforementioned components 102-116 can vary considerably depending on the type of vehicle using these components, such as a wheeled land vehicle, e.g., a car, van, truck, or bus. Prime mover 104 may include one or more electric motors and / or internal combustion engines (etc.). Energy sources may include, for example, fuel systems (e.g., providing gasoline, diesel, hydrogen, etc.), battery systems, solar panels or other renewable energy sources, and / or fuel cell systems. The drivetrain 108 may include wheels and / or tires, as well as a transmission and / or any other mechanical drive components to convert the output of the prime mover 104 into vehicle motion; and one or more brakes configured to controllably stop or slow the vehicle 100, and directional or steering components suitable for controlling the trajectory of the vehicle 100 (e.g., rack and pinion steering linkages that enable one or more wheels of the vehicle 100 to pivot about a generally vertical axis to change the angle of the wheel's plane of rotation relative to the vehicle's longitudinal axis). In some embodiments, a combination of powertrain and energy source may be used (e.g., in the case of an electric / gas hybrid vehicle), and in some cases, multiple motors (e.g., dedicated to individual wheels or axles) may be used as prime movers.

[0051] Steering control 112 may include one or more actuators and / or sensors for controlling and receiving feedback from steering or directional components to enable vehicle 100 to follow a desired trajectory. Powertrain control 114 may be configured to control the output of powertrain 102, such as controlling the output power of prime mover 104, controlling the gear position of transmission in transmission assembly 108, etc., thereby controlling the speed and / or direction of vehicle 100. Braking control 116 may be configured to control one or more brakes that slow down or stop vehicle 100, such as disc brakes or drum brakes coupled to the wheels of the vehicle.

[0052] Other vehicle types, including but not limited to off-road vehicles, all-terrain or tracked vehicles, and construction equipment, may use different powertrains, transmissions, energy sources, steering controls, powertrain controls, and braking controls. Furthermore, in some implementations, components may be combined; for example, vehicle steering control may be primarily handled by altering the output of one or more prime movers.

[0053] Various levels of automated driving control of the vehicle 100 can be implemented in the vehicle control system 120, which may include one or more processors 122 and one or more memories 124, wherein each processor 122 is configured to execute program code instructions 126 stored in the memory 124. The one or more processors may include, for example, one or more graphics processing units (“one or more GPUs”) and / or one or more central processing units (“one or more CPUs”).

[0054] Sensor 130 may include various sensors suitable for collecting information from the vehicle's surrounding environment for controlling vehicle operation. For example, sensor 130 may include radar sensor 134, LIDAR (Light Detection and Ranging) sensor 136, 3D positioning sensor 138, such as an accelerometer, gyroscope, magnetometer, or any satellite navigation system (such as GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), BeiDou Navigation Satellite System (BDS), Galileo, compass, etc.). 3D positioning sensor 138 can be used to determine the vehicle's position on Earth using satellite signals. Sensor 130 may include camera 140 and / or IMU (Inertial Measurement Unit) 142. Camera 140 may be a single-frame or stereo camera and may record still and / or video images. IMU 142 may include multiple gyroscopes and accelerometers capable of detecting linear and rotational motion of the vehicle in three directions. One or more encoders (not shown) (such as wheel encoders) can be used to monitor the rotation of one or more wheels of vehicle 100. Each sensor 130 can output sensor data at various data rates, which may differ from the data rates of other sensors 130.

[0055] The output of sensor 130 can be provided to a set of control subsystems 150, including a positioning subsystem 152, a planning subsystem 156, a perception subsystem 154, and a control subsystem 158. The positioning subsystem 152 can perform functions such as accurately determining the position and orientation (sometimes referred to as "pose") of vehicle 100 in its surrounding environment, and typically within a reference frame. As part of generating labeled autonomous vehicle data, the position of the autonomous vehicle can be compared with the position of another vehicle in the same environment. The perception subsystem 154 can perform functions such as detecting, tracking, identifying, and / or recognizing objects in the environment surrounding vehicle 100. According to some embodiments, machine learning models can be used to track objects. The planning subsystem 156 can perform functions such as planning a trajectory for vehicle 100 over a time period given a desired destination and static and moving objects in the environment. According to some embodiments, machine learning models can be used to plan vehicle trajectories. The control subsystem 158 can perform functions such as generating appropriate control signals to control various controls in the vehicle control system 120 to achieve the planned trajectory of vehicle 100. Machine learning models can be used to generate one or more signals to control the autonomous vehicle to implement the planned trajectory.

[0056] It can be used Figure 1 Multiple sensors of the type shown can be used to achieve redundancy and / or coverage of different areas around the vehicle; other types of sensors may also be used. Various types and / or combinations of control subsystems can be used. Some or all of the functions of subsystems 152-158 can be implemented by program code instructions 126 residing in one or more memories 124 and executed by one or more processors 122, and these subsystems 152-158 may, in some cases, be implemented using the same processor and / or memory. Subsystems can be implemented, at least in part, using various special-purpose circuit logics, various processors, various field-programmable gate arrays (“FPGAs”), various application-specific integrated circuits (“ASICs”), various real-time controllers, etc., and as described above, multiple subsystems can utilize circuits, processors, sensors, and / or other components. Furthermore, the various components in the vehicle control system 120 can be networked in various ways.

[0057] In some embodiments, vehicle 100 may further include an auxiliary vehicle control system (not shown), which may serve as a redundancy or backup control system for vehicle 100. In some embodiments, the auxiliary vehicle control system is capable of fully operating the autonomous vehicle 100 in the event of an adverse event detected in the primary vehicle control system 120, while in other embodiments, the auxiliary vehicle control system may have only limited functionality, such as performing a controlled stop of vehicle 100 in response to an adverse event detected in the primary vehicle control system 120. In other embodiments, the auxiliary vehicle control system may be omitted.

[0058] It can be implemented using various architectures, including various combinations of software, hardware, circuit logic, sensors, and networks. Figure 1 The various components are shown. Each processor may be implemented, for example, as a microprocessor, and each memory may represent a random access memory (“RAM”) device, which includes main memory and any supplementary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), read-only memory, etc. Furthermore, each memory may be considered to include: memory storage physically located elsewhere in vehicle 100, such as any cache memory in the processor; and any storage capacity used as virtual memory, such as storage on a mass storage device or another computer controller. Figure 1 One or more processors, or completely independent processors, shown in the diagram, can be used in vehicle 100 to implement additional functions beyond the purpose of autonomous driving control, such as controlling the entertainment system, operating doors, lights, convenience functions, etc.

[0059] In addition, for additional storage, vehicle 100 may include one or more mass storage devices, such as removable disk drives, hard disk drives, direct access storage devices (“DASD”), optical disc drives (e.g., CD drives, DVD drives, etc.), solid-state storage drives (“SSD”), network attached storage, storage area networks and / or tape drives, etc.

[0060] In addition, vehicle 100 may include user interface 164 to enable vehicle 100 to receive multiple inputs from a user or operator and generate outputs thereto, such as one or more displays, touchscreens, voice and / or gesture interfaces, buttons, and other tactile controls. Alternatively, user input may be received via another computer or electronic device (e.g., via an application on a mobile device or via a network interface).

[0061] Furthermore, vehicle 100 may include one or more network interfaces, such as network interface 162, adapted to communicate with one or more networks 170 (e.g., local area network (“LAN”), wide area network (“WAN”), wireless network, and / or the Internet, etc.) to allow communication of information with other computers and electronic devices, including, for example, a central service such as a cloud service, from which vehicle 100 receives environmental and other data for its autonomous driving control. Data collected by one or more sensors 130 may be uploaded via network 170 to computing system 172 for further processing. In some embodiments, timestamps may be added to each instance of vehicle data before uploading.

[0062] Figure 1Each processor shown, as well as the various additional controllers and subsystems disclosed herein, typically operates under the control of an operating system and executes or otherwise depends on various computer software applications, components, programs, objects, modules, data structures, etc., as will be described in more detail below. Furthermore, the various applications, components, programs, objects, modules, etc., may also execute, for example, in a distributed, cloud-based, or client-server computing environment, on one or more processors in another computer coupled to vehicle 100 via network 170, thereby distributing the processing required to implement the functions of the computer program to multiple computers and / or services on the network.

[0063] Generally, routines executed to implement the various embodiments described herein, whether implemented as part of an operating system or as a specific application, component, program, object, module, or sequence of instructions, or even a subset thereof, are referred to herein as "program code." Program code may include one or more instructions that reside at different times in different memories and storage devices, and when read and executed by one or more processors, perform steps necessary to perform the steps or elements embodying various aspects of this disclosure. Furthermore, while embodiments have been and will be described below in the context of fully functional computers and systems, it should be understood that the various embodiments described herein can be distributed as program products in various forms, and can be implemented regardless of the specific type of computer-readable medium used to actually perform the distribution.

[0064] Examples of computer-readable media include tangible, non-transient media such as volatile and non-volatile memory devices, floppy disks and other removable disks, solid-state drives, hard disk drives, magnetic tapes and optical discs (e.g., CD-ROMs, DVDs, etc.).

[0065] Furthermore, the various program codes described below can be identified based on the application in which they are implemented in a particular implementation. Any particular program nomenclature used below is for convenience only, and therefore this disclosure should not be limited to use only in any particular application identified and / or implied by that nomenclature. Moreover, given the virtually endless ways in which computer programs can be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functionality can be distributed among various software layers residing within a typical computer (e.g., operating systems, libraries, APIs, applications, applets, etc.), this disclosure is not limited to the specific organization and distribution of program functionality described herein.

[0066] 2. LiDAR for automotive applications

[0067] Trucks may include LIDAR systems (e.g., Figure 1 The vehicle control system 120 in Figure 5The LIDAR sensor system 500 described herein, and other systems thereof. In some embodiments, the LIDAR sensor system 500 may use frequency modulation to encode an optical signal and use optics to scatter the encoded optical signal into free space. By detecting the frequency difference between the encoded optical signal and the returned signal reflected from the object, the frequency modulation (FM) LIDAR sensor system can determine the position of the object and / or accurately measure the velocity of the object using the Doppler effect. In some embodiments, the FM LIDAR sensor system may use continuous wave (referred to as "FMCW LIDAR") or quasi-continuous wave (referred to as "FMQW LIDAR"). In some embodiments, the LIDAR sensor system may use phase modulation (PM) to encode an optical signal and use optics to scatter the encoded optical signal into free space.

[0068] In some cases, an object (e.g., a pedestrian wearing dark clothing) may have low reflectivity because it reflects only a small amount (e.g., 10% or less) of the light that hits the object back to the sensors of an FM or PM LIDAR sensor system (e.g., Figure 1 (Sensor 130 in the system). In other cases, an object (e.g., a flashing road sign) may have a high reflectivity (e.g., more than 10%) because it reflects a large amount of light that hits the object back to the sensor of the FM LIDAR sensor system.

[0069] Regardless of an object's reflectivity, FM LIDAR sensor systems can detect (e.g., classify, identify, discover) objects at much greater distances (e.g., twice as far) than conventional LIDAR sensor systems. For example, an FM LIDAR sensor system can detect low-reflectivity objects at a distance of 300 meters and high-reflectivity objects at a distance of 400 meters.

[0070] To achieve this improvement in detection capability, the FM LIDAR sensor system can use sensors (e.g., Figure 1 (Sensor 130 in the example). In some embodiments, these sensors can be single-photon sensitive, meaning they can detect the smallest possible amount of light. While FM LIDAR sensor systems can use infrared wavelengths (e.g., 950 nm, 1550 nm, etc.) in some applications, they are not limited to the infrared wavelength range (e.g., near-infrared: 800 nm–1500 nm; mid-infrared: 1500 nm–5600 nm; and far-infrared: 5600 nm–1,000,000 nm). By operating FM or PM LIDAR sensor systems in infrared wavelengths, FM or PM LIDAR sensor systems can broadcast stronger light pulses or beams than conventional LIDAR sensor systems.

[0071] Therefore, by detecting objects at greater distances, FM LIDAR sensor systems can have more time to react to unexpected obstacles. In fact, even a few milliseconds of extra time can improve response time and comfort, especially for heavy vehicles (e.g., commercial trucks) traveling at highway speeds.

[0072] FM LIDAR sensor systems can provide accurate velocity for each data point in real time. In some implementations, velocity measurement is achieved using the Doppler effect, which offsets the frequency of light received from an object based on at least one of radial velocity (e.g., the direction vector between the detected object and the sensor) or the frequency of a laser signal. For example, for a velocity encountered on a road at less than 100 meters per second (m / s), such an offset at a wavelength of 1550 nanometers (nm) corresponds to a frequency offset of less than 130 MHz. This frequency offset is very small and therefore difficult to detect directly in the optical domain. However, by using coherent detection in FMCW, PMCW, or FMQW LIDAR sensor systems, the signal can be converted to the RF domain, allowing the frequency offset to be calculated using various signal processing techniques. This enables autonomous vehicle control systems to process incoming data much faster.

[0073] Instantaneous velocity calculation also makes it easier for FM LIDAR sensor systems to identify distant or sparse data points as objects and / or track how these objects move over time. For example, FM LIDAR sensors (e.g., Figure 1 The sensor 130 in the system may only receive a few returns of objects 300 meters away (e.g., hits), but if these returns give a speed value of interest (e.g., moving toward the vehicle at a speed >70 mph), the FM LIDAR sensor system and / or the autonomous vehicle control system can determine the appropriate weights for the probability of being associated with the object.

[0074] The faster identification and / or tracking capabilities of FM LIDAR sensor systems give autonomous vehicle control systems more time to maneuver the vehicle. A better understanding of the speed at which objects are moving also allows autonomous vehicle control systems to plan better responses.

[0075] Compared to traditional LiDAR sensor systems, FM LiDAR sensor systems can have less static interference. That is, traditional LiDAR sensor systems, designed to be more sensitive to light, typically perform poorly in bright sunlight. These systems are also susceptible to crosstalk (e.g., when sensors are confused by each other's light pulses or beams) and self-interference (e.g., when a sensor is confused by its own previous light pulses or beams). To overcome these drawbacks, vehicles using traditional LiDAR sensor systems typically require additional hardware, complex software, and / or more computing power to manage this "noise."

[0076] In contrast, FM LIDAR sensor systems do not encounter these types of problems because each sensor is specifically designed to respond only to its own optical characteristics (e.g., beam, wave, pulse). If the returned light does not match the timing, frequency, and / or wavelength of the original emitted light, the FM sensor can filter (e.g., remove, ignore, etc.) that data point. Therefore, FM LIDAR sensor systems produce (e.g., generate, export, etc.) more accurate data with fewer hardware or software requirements, resulting in smoother driving.

[0077] Compared to traditional LiDAR sensor systems, FM LiDAR sensor systems are easier to scale. As more autonomous vehicles (e.g., cars, commercial trucks, etc.) appear on the road, vehicles powered by FM LiDAR sensor systems may not need to deal with interference issues caused by sensor crosstalk. Furthermore, FM LiDAR sensor systems use lower peak optical power than traditional LiDAR sensors. Therefore, some or all of the optical components of an FM LiDAR can be manufactured on a single chip, which has its own advantages, as described in this article.

[0078] 2.1 Commercial Trucks

[0079] Figure 2This is a block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to some embodiments. Environment 100B includes a commercial truck vehicle 102B for hauling cargo 106B. In some embodiments, the commercial truck vehicle 102B may include a vehicle configured for long-haul freight, regional freight, intermodal freight (i.e., where a road-based vehicle is used as one of a variety of modes of transport to move cargo), and / or any other road-based freight application. In some embodiments, the commercial truck 102B may be a flatbed truck, a refrigerated truck (e.g., a refrigerated truck), a ventilated van (e.g., a dry van), a mobile truck, etc. In some embodiments, cargo 106B may be cargo and / or agricultural products. In some embodiments, the commercial truck 102B may include a trailer for carrying cargo 106B, such as a flatbed trailer, a low-floor trailer, a ladder trailer, an expandable flatbed trailer, a side-mounted trailer, etc.

[0080] Environment 100B includes object 110B (in Figure 2 (As shown in the image, another vehicle), the object is located within a distance of 30 meters or less from the truck.

[0081] Commercial truck 102B may include LIDAR sensor system 104B (e.g., FM LIDAR sensor system, Figure 1 The vehicle control system 120 in Figure 5 The LIDAR sensor system 500 is used to determine the distance to object 110B and / or measure the velocity of object 110B. Although Figure 2 A LiDAR sensor system 104B is shown mounted on the front of a commercial truck 102B, but the number of LiDAR sensor systems and the mounting areas of the LiDAR sensor systems on the commercial truck are not limited to a specific number or a specific area. The commercial truck 102B may include any number of LiDAR sensor systems 104B (or components thereof, such as sensors, modulators, coherent signal generators, etc.) mounted in any area of ​​the commercial truck 102B (e.g., front, rear, side, top, bottom, under, and / or bottom) to facilitate the detection of objects in any free space relative to the commercial truck 102B.

[0082] As shown in the figure, the LIDAR sensor system 104B in environment 100B can be configured to detect objects (e.g., another vehicle, bicycle, tree, road sign, pothole, etc.) that are close to the commercial truck 102B (e.g., 30 meters or less).

[0083] Figure 3This is a block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to some embodiments. Environment 100C includes the same components contained in Environment 100B (e.g., commercial truck 102B, cargo 106B, LIDAR sensor system 104B, etc.).

[0084] Environment 100C includes object 110C (in) Figure 3 (As shown in the diagram, another vehicle), the object 110C is located within a distance range of (i) greater than 30 meters and (ii) equal to or less than 150 meters from the commercial truck 102B. As shown, the LIDAR sensor system 104B in the environment 100C can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a distance (e.g., 100 meters) from the commercial truck 102B.

[0085] Figure 4 This is a block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to some embodiments. Environment 100D includes the same components contained in Environment 100B (e.g., commercial truck 102B, cargo 106B, LIDAR sensor system 104B, etc.).

[0086] Environment 100D includes object 110D (in Figure 4 (As shown in the image, another vehicle), the object 110D is located at a distance of more than 150 meters from the commercial truck 102B. As shown, the LIDAR sensor system 104B in the environment 100D can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a distance (e.g., 300 meters) from the commercial truck 102B.

[0087] In commercial truck applications, due to increased weight and the resulting need for longer stopping distances, effective object detection across the entire range is crucial. Because of these advantages, FM LIDAR sensor systems (e.g., FMCW and / or FMQW systems) or PM LIDAR sensor systems are well-suited for commercial truck applications. Therefore, commercial trucks equipped with such systems can enhance their ability to transport people and goods over short or long distances. In various implementations, such FM or PM LIDAR sensor systems can be used in semi-autonomous driving applications (where the commercial truck has a driver and certain functions of the commercial truck are operated automatically using the FM or PM LIDAR sensor system) or fully autonomous driving applications (where the commercial truck is operated entirely by the FM or LIDAR sensor system alone or in combination with other vehicle systems).

[0088] 3. LIDAR sensor system

[0089] Figure 5An example of a LIDAR sensor system 500 is depicted. The LIDAR sensor system 500 can be used to determine parameters about an object, such as range and velocity, and output these parameters to a remote system. For example, the LIDAR sensor system 500 can output parameters for use by a vehicle controller (e.g., vehicle controller 598) that can control the operation of a vehicle in response to the received parameters, or by a display that can present a representation of the parameters. The LIDAR sensor system 500 can be a coherent detection system. The LIDAR sensor system 500 can be used to implement a reference... Figure 1-4 The system described includes various features and components. The LIDAR sensor system 500 may include components for performing various detection methods, such as operating as an amplitude-modular LIDAR system or a coherent LIDAR system. The LIDAR sensor system 500 can be used to perform time-of-flight range determination. In some embodiments, various components or combinations of components of the LIDAR sensor system 500, such as the laser source 504 and the modulator 514, may be housed in the same housing, disposed in the same circuit board or other electronic components, or otherwise integrated. In some embodiments, various components or combinations of components of the LIDAR sensor system 500 may be provided as separate components, for example, by using an optical coupler (e.g., an optical fiber) for generating and / or receiving optical signals (such as a beam of light), or by using a wired or wireless electronic connection for generating and / or receiving electrical (e.g., data) signals.

[0090] The LIDAR sensor system 500 may include a laser source 504 that generates and emits a beam 506 (such as a carrier beam). A beam splitter 508 may split the beam 506 into a beam 510 and a reference beam 512 (e.g., a reference signal). In some embodiments, any suitable optical, electronic, or optoelectronic components may be used to provide the beam 510 and the reference beam 512 from the laser source 504 to other components.

[0091] Modulator 514 can modulate one or more properties of input beam 510 to generate beam 516 (e.g., a target beam). In some embodiments, modulator 514 can modulate the frequency of input beam 510 (e.g., the optical frequency corresponding to the wavelength of light, where c = λν, where c is the speed of light, λ is the wavelength, and ν is the frequency). For example, modulator 514 can linearly modulate the frequency of input beam 510 such that the frequency of beam 516 increases or decreases linearly with time. As another example, modulator 514 can non-linearly (e.g., exponentially) modulate the frequency of input beam 510. In some embodiments, modulator 514 can modulate the phase of input beam 510 to generate beam 516. However, modulation techniques are not limited to frequency modulation and phase modulation. Any suitable modulation technique can be used to modulate one or more properties of the beam. Figure 5 Modulator 514 can modulate beam 510 after beam 506 is split by beam splitter 508, so that reference beam 512 is not modulated, or modulator 514 can modulate beam 506 and provide modulated beam to beam splitter 508 so that beam splitter 508 splits it into target beam and reference beam.

[0092] The beam 516 used to output the transmitted signal can have most of the energy of the beam 506 output by the laser source 504, while the reference beam 512 can have much less energy, but enough to be mixed with the returning beam 548 (e.g., return light) scattered from the object. The reference beam 512 can be used as a local oscillator (LO) signal. The reference beam 512 passes through a reference path and can be provided to the mixer 560. The amplifier 520 can amplify the beam 516 to output beam 522.

[0093] The LIDAR sensor system 500 may include an optical module 524 that can receive a light beam 522. The optical module 524 may be a free-space optics device. For example, the optical module 524 may include one or more optics devices (e.g., lenses, mirrors, waveguides, grating couplers, prisms, waveplates) arranged with gaps (e.g., air gaps) between the optics devices to allow free-space light transmission (e.g., not all light is coupled between optics via optical fibers). The optical module 524 may perform functions such as collimating, filtering, and / or polarizing the light beam 522 to output the light beam 530 to an optics device 532 (e.g., a scanning optics device).

[0094] refer to Figure 6 The optical module 524 may include at least one collimator 604 and at least one circulator 608. For example, the circulator 608 may be located between the collimator 604 and the circulator 608. Figure 5 Between the optical devices 532. The circulator 608 can receive the collimated beam 612 output by the collimator 604 and convert the beam 616 (e.g., Figure 5 The light beam 530 depicted is output to the optics 532. In some embodiments, the circulator 608 may be located between the laser source 504 and the collimator 604. At least one of the collimator 604 or the circulator 608 may be a free-space optics (and may be coupled to each other in free space), such as by optical coupling via an air gap instead of an optical fiber.

[0095] Further reference Figure 5Optical module 524 can receive the return beam 548 from optical device 532 and provide the return beam 548 to mixer 560. Optical device 532 may be: a scanning optics, such as one or more steering mirrors or polygonal reflectors or deflectors, for adjusting the angle of the received beam relative to the output beam based on the orientation of the outer surface (e.g., a section) of the optics relative to the received beam; or a solid-state component (e.g., a phased array, an electro-optic crystal) configured to modify the direction of the received light.

[0096] Optical element 532 can define a field of view 544 corresponding to the angle scanned (e.g., swept) by the beam 542 (e.g., the emitted beam). For example, the beam 542 can be scanned on a specific plane, such as an azimuth plane or an elevation plane (e.g., relative to an object coupled to the LIDAR sensor system 500, such as an autonomous vehicle). Optical element 532 can be oriented such that the field of view 544 sweeps across the azimuth plane relative to the optical element 532.

[0097] At least one motor 540 may be coupled to the optical device 532 to control at least one of the positions or orientations of the optical device 532 relative to the light beam 530. For example, when the optical device 532 includes a reflector or deflector, the motor 540 may rotate the optical device 532 such that the surface of the optical device 532 receiving the light beam 530 changes in angle or orientation relative to the light beam 530, thereby causing the light beam 542 to change in angle or orientation when it is output from the optical device 532.

[0098] The beam 542 may be output from the optics 532 and may be reflected by an object (not shown) or otherwise scattered as a return beam 548 (e.g., a return signal). The return beam 548 may be received on a receiving path (which may include a circulator 528) and provided to the mixer 560.

[0099] Mixer 560 may be an optical mixer, such as a 90-degree optical mixer. Mixer 560 may receive a reference beam 512 and a return beam 548, and mix the reference beam 512 and the return beam 548 to output a signal 564 in response to the reference beam 512 and the return beam 548. Signal 564 may include an in-phase (I) component 568 and a quadrature (Q) component 572.

[0100] The LIDAR sensor system 500 may include a receiver 576 that receives a signal 564 from a mixer 560. The receiver 576 may generate a signal 580 in response to the signal 564, which may be an electronic (e.g., radio frequency) signal. The receiver 576 may include one or more photodetectors that output the signal 580 in response to the signal 564.

[0101] The LIDAR sensor system 500 may include a processing system 590, which can use a reference... Figure 1 The vehicle control system 120 described herein is implemented using these features. The processing system 590 can process received data (such as signal 580) regarding the returned beam 548 to determine parameters (such as range and speed) about the object. The processing system 590 may include a scanner controller 592 that can provide scanning signals to control the operation of optics 532, such as controlling a motor 540 to rotate optics 532 to achieve a target scanning mode, such as a sawtooth scanning mode or a step function scanning mode. The processing system 590 may include a Doppler compensator 594 that can determine the sign and magnitude of the Doppler frequency shift associated with processing the returned beam 548, and a correction range and any other corrections based thereon. The processing system 590 may include a modulator controller 596 that can send one or more electrical signals to drive modulator 514.

[0102] The processing system 590 may include a vehicle controller 598 or be communicatively coupled to the vehicle controller 598 to control the operation of a vehicle equipped with the LIDAR sensor system 500 (e.g., providing fully or semi-autonomous driving control of the vehicle). For example, the vehicle controller 598 may be implemented by at least one of the vehicle's LIDAR sensor system 500 or control circuitry. The vehicle controller 598 may control the operation of the vehicle in response to at least one of the range to an object or the speed of an object determined by the processing system 590. For example, the vehicle controller 598 may transmit control signals to at least one of the vehicle's steering system or braking system to control at least one of the vehicle's speed or direction.

[0103] 3.1 A LiDAR sensor system including a grating coupler for multi-directional reception

[0104] Figure 7 A block diagram depicting an example of a LIDAR sensor system 700 is provided. The LIDAR sensor system 700 can be combined with separate references. Figure 5 and 6 The LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 700 can facilitate transmit-receive compensation, i.e., taking into account the time delay or other offset caused by the round-trip path of the emitted beam, which is output from the LIDAR sensor system 700, reflected by an object, or otherwise scattered, and then returned as a return beam to the LIDAR sensor system 700 for detection and processing, which could otherwise affect the characteristics of the LIDAR sensor system 700, such as the signal-to-noise ratio.

[0105] The LIDAR sensor system 700 may include a chip 705 on which various components of the LIDAR sensor system 700, including a transmitter 710 and a receiver 712, can be provided. For example, the chip 705 may be a photonic integrated chip, enabling the implementation of various components of the LIDAR sensor system 700 for generating, modulating, and processing optical signals, as well as performing photonic operations. The chip 705 may be a semiconductor circuit chip. The chip 705 may be made of at least one III-V semiconductor material. For example, the chip 705 may be made of silicon or pure silicon. The chip 705 may be made of gallium nitride. The chip 705 may be made of aluminum nitride. The chip 705 may be made of both gallium nitride and pure silicon.

[0106] The LIDAR sensor system 700 includes at least one transmitter 710. The transmitter 710 can receive a light beam (e.g., a reference beam). Figure 5 and 6 (Description of various light beams) and outputs a emitted light beam 735 with specific characteristics (such as direction, polarization or various combinations thereof).

[0107] Emitter 710 may include at least one grating coupler 715 (e.g., a first grating coupler). The grating coupler 715 may be a structure having a plurality of spaced-apart channels (such as parallel channels), which may have various shapes and have the same or different dimensions. The grating coupler 715 may be a structure formed by etching on chip 705. The grating coupler 715 may also be a structure formed by depositing material on chip 705.

[0108] The grating coupler 715 can be configured to couple light from the chip 705 away, such as into free space away from the chip 705. For example, the grating coupler 715 can couple light from the chip 705 away in a two-dimensional mode (such as two-dimensional polarization). Therefore, the grating coupler 715 can output an emitted beam 735, such as a beam based on the beam output by the laser source 504.

[0109] The grating coupler 715 can output an emitted beam 735 with an emitted polarization 795. For example, various components upstream or downstream of the grating coupler 715 (e.g., optical module 524) can be used to control the polarization of the emitted beam 735.

[0110] The LIDAR sensor system 700 may include at least one scanner 740, such as a steering mirror. (For example, a brief reference...) Figure 5 The scanner 740 can be coupled to the motor 540, so that the scanner 740 can rotate in a direction that is guided toward the scanner 740 relative to the emitted beam 735.

[0111] Scanner 740 can scan bidirectionally. For example, scanner 740 can scan in a first direction 760 and a second direction 765 (e.g., relative to a reference). Figure 5 (Described axis 534). Scanner 740 can receive the emitted beam 735 from transmitter 710 and direct the emitted beam 735 toward the environment surrounding LIDAR sensor system 700. (As described) Figure 7 As shown, object 702 may be present in the environment. Scanner 740 may receive a return beam 755 reflected or scattered from object 702 on emitted beam 735. During the time required for emitted beam 735 to reach object 702 and for return beam 755 to return from object 702 to scanner 740, scanner 740 may have rotated by a specific angle, as described in more detail below. Scanner 740 may provide return beam 755 to receiver 712.

[0112] Receiver 712 may include multiple grating couplers. For example, receiver 712 may include grating coupler 725 and grating coupler 730. Grating couplers 725 and 730 may be provided or formed in a similar or identical manner to grating coupler 715. Grating couplers 715, 725, and 730 may be arranged in an array on chip 705 (e.g., at least two parallel spaced lines may extend through each grating coupler 715, 725, and 730). Grating couplers 715, 725, and 730 may be arranged in the focal plane of scanner 740 or at least one of one or more optical components between grating couplers 715, 725, and 730 and scanner 740.

[0113] Grating couplers 725 and 730 may be spaced apart from grating coupler 715. For example, grating coupler 725 may be spaced apart from grating coupler 715 by a first spacing (e.g., a first distance). The first spacing may be associated with a first target range of distance scanner 740 for detecting object 702. For example, the first target range may be within a distance range of distance scanner 740, for which a expected signal-to-noise ratio is determined to be greater than a threshold signal-to-noise ratio for at least one of the range to object 702 or the velocity of object 702. The first spacing may be between about 12 micrometers (μm) and about 16 μm. For example, grating coupler 725 may be spaced apart from grating coupler 715 by about 14 μm.

[0114] The grating coupler 730 may be spaced apart from the grating coupler 715 by a second spacing (e.g., a second distance). This second spacing may be associated with a second target range of the distance scanner 740. The second target range may be larger than the first target range. The second spacing may be between approximately 10 μm and approximately 20 μm. For example, the grating coupler 730 may be spaced apart from the grating coupler 715 by approximately 12 micrometers.

[0115] Raster couplers 725 and 730 can receive the return beam 755 provided by scanner 740. Raster couplers 725 and 730 can couple light (e.g., the return beam 755) from free space to chip 705. As previously described, scanner 740 can rotate within the time required for the emitted beam 735 to travel to object 702 and return as the return beam 755 to receiver 712, which can cause angular displacement of the return beam 755 in the direction scanned by scanner 740. When the return beam 755 is provided to receiver 712, the angular displacement can manifest as translation in the focal plane. Translation can be called focal plane drift. Since grating couplers 725 and 730 can couple light to chip 705 and are distinct from each other and spatially separated, grating couplers 725 and 730 can be provided for both directions of focal plane drift. Furthermore, the translation distance can be optimized for the target time of the emitted beam 735 traveling to the object 702 and the return beam 755 returning from the object 702 to the receiver 712, and thus for a specific range to the object 702 (since the speeds of the emitted beam 735 and the return beam 755 are known).

[0116] The return beam 755 may have components associated with various polarizations, such as based on how the emitted beam 735 is output and / or passes through a device such as the optical module 524. Therefore, the scanner 740 may provide a first component 770 of the return beam 755, which may be associated with a first polarization 780, and the grating coupler 725 may receive the first component 770 of the return beam 755. The scanner 740 may also provide a second component 775 of the return beam 755 associated with a second polarization 785, and the grating coupler 730 may receive the second component 775.

[0117] The first polarization 780 can be different from the second polarization 785. The emitted polarization 795 can be the same as the first polarization 780. For example, grating coupler 715 can output the emitted beam 735 with the first polarization 780. Grating couplers 725 and 730 can receive the returned beam 755 with either the first polarization 780 or the second polarization 785. The second polarization 785 can be orthogonal to the first polarization 780.

[0118] Grating couplers 725 and 730 can be configured to receive only a single polarization of a beam (e.g., light). Grating couplers 725 and 730 can also receive light with different polarizations. For example, grating coupler 725 can receive light with the same polarization as the emitted beam 735, while grating coupler 730 can receive light with a polarization orthogonal to the emitted beam 735. Grating couplers 725 and 730 can also be configured to receive light with the same polarization as each other. For example, grating couplers 725 and 730 can (only) receive light with a polarization orthogonal to the emitted beam 735, such as... Figure 7 As shown, or the grating couplers 725 and 730 can (only) receive light with the same polarization as the emitted beam 735.

[0119] Receiver 712 may output at least one signal based on a first component 770 of the returned beam 755 received by grating coupler 725 and a second component 775 of the returned beam 755 received by grating coupler 730. The at least one signal output by receiver 712 may be used by various systems described herein (such as vehicle control system 120) to determine at least one of the range to object 702 or the speed of object 702, to control the operation of an autonomous vehicle, such as in response to at least one of the range or speed.

[0120] Figure 8 This is a block diagram illustrating an example of the optical components of system 800. System 800 may include components of the various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, system 800 may be used to implement a single-polarization receiver and a switched local oscillator.

[0121] like Figure 8 As shown, system 800 may include a transmitting antenna 810, which can be implemented via a grating coupler 715 of transmitter 710. For example, transmitting antenna 810 may be an optical antenna integrated onto chip 705. Transmitting antenna 810 can couple a transmitted beam 735 into free space. Transmitting antenna 810 can be oriented relative to the surface on which transmitting antenna 810 is located at an angle corresponding to the polarization of the transmitted beam 735.

[0122] System 800 may include a local oscillator 815. Local oscillator 815 may output a local oscillator (LO) signal. For example, local oscillator 815 may actively switch the LO signal between at least two mixers based on the scanning direction of scanner 740, as described further below. For example, local oscillator 815 may output a first LO signal and a second LO signal. The LO signal may be similar to or the same as reference beam 512. For example, local oscillator 815 may transmit a first LO signal, such as reference beam 820. Local oscillator 815 may transmit a second LO signal, such as reference beam 830. Switching the LO signal by local oscillator 815 can reduce the amount of power required by local oscillator 815.

[0123] System 800 may include a receiving antenna 825 of receiver 712. The receiving antenna 825 may be implemented by a grating coupler 725 of receiver 712. For example, the receiving antenna 825 may be an optical antenna integrated onto chip 705. The receiving antenna 825 may couple a first component 770 of the returned beam 755 from free space to chip 705. The receiving antenna 825 may be oriented relative to the surface on which the receiving antenna 825 is located at an angle corresponding to a first polarization 780 of the first component 770 of the returned beam 755.

[0124] The receiving antenna 825 can receive the returned beam 755. For example, the receiving antenna 825 can receive a first component 770 of the returned beam 755. Therefore, the receiving antenna 825 can be oriented with the same polarization as the first component 770 of the returned beam 755. For example, the receiving antenna 825 can have the same polarization as the first polarization 780. The receiving antenna 825 can provide the first component 770 of the returned beam 755 to other elements of the system 800, as described in more detail below.

[0125] System 800 may include a receiving antenna 835 of receiver 712. The receiving antenna 835 may be implemented by a grating coupler 730 of receiver 712. For example, the receiving antenna 835 may be an optical antenna integrated onto chip 705. The receiving antenna 835 may couple a second component 775 of the returned beam 755 from free space to chip 705. The receiving antenna 835 may be oriented relative to the surface on which the receiving antenna 835 is located at an angle corresponding to a second polarization 785 of the second component 775 of the returned beam 755.

[0126] The receiving antenna 835 can receive the returned beam 755. For example, the receiving antenna 835 can receive a second component 775 of the returned beam 755. Therefore, the receiving antenna 835 can be oriented with the same polarization as the second component 775 of the returned beam 755. For example, the receiving antenna 835 can have the same polarization as the second polarization 785. The receiving antenna 835 can provide the second component 775 of the returned beam 755 to other elements of the system 800, as described in more detail below.

[0127] System 800 may include at least one mixer. This mixer may be similar to or the same as mixer 560. For example, system 800 may include mixer 840, which functions similarly to mixer 560. For example, system 800 may include mixer 845, which functions similarly to mixer 560. Mixers 840 and 845 may each be a 2x2 optical mixer. Mixers 840 and 845 may each be an optical mixer. For example, mixers 840 and 845 may each be a 90-degree optical mixer. For example, mixers 840 and 845 may each be a 2x4 optical mixer.

[0128] Mixers 840 and 845 can receive signals. For example, mixer 840 can receive a reference beam 820, such as a first LO signal. For example, mixer 840 can receive a first component 770 of the returned beam 755 from receiving antenna 825. For example, mixer 845 can receive a reference beam 830, such as a second LO signal. For example, mixer 845 can receive a second component 775 of the returned beam 755 from receiving antenna 835.

[0129] Mixers 840 and 845 can each output a signal. For example, the output signal can be based on the signal received by each of mixers 840 and 845 from receiving antennas 825 and 835. For example, the output signal can be based on the signal received by each of mixers 840 and 845 from local oscillator 815. For example, mixers 840 and 845 can output signals in response to the return beam 755 and reference beams 820 and 830. For example, mixers 840 and 845 can mix the return beam 755 and reference beams 820 and 830 and output signals respectively. Mixer 840 can output signal 850. Signal 850 can be in response to and based on a first component 770 of the return beam 755 and reference beam 820. Mixer 845 can output signal 855. Signal 855 can be in response to and based on a second component 775 of the return beam 755 and reference beam 830. Mixers 840 and 845 can provide signals 850 and 855 to grating couplers 725 and 730, respectively, such as causing grating couplers 725 and 730 to provide components 770 and 775 of the returned beam 755 to optical detection devices, such as one or more photodetectors of receiver 712.

[0130] Figure 9 It includes Figure 8 A block diagram illustrating an example of a LIDAR sensor system 900 with optical components. The LIDAR sensor system 900 can be combined with [other components] as shown in the reference diagrams. Figure 5 and 6 The LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 900 can facilitate transmit-receive compensation, including taking into account time delays or other offsets caused by the round-trip path of the emitted beam, which is output from the LIDAR sensor system 700, reflected by an object, or otherwise scattered, and then returned as a return beam to the LIDAR sensor system 900 for detection and processing, which could otherwise affect the characteristics of the LIDAR sensor system 900, such as the signal-to-noise ratio.

[0131] The LIDAR sensor system 900 may include a grating coupler 715 configured to output an emitted beam 735. The LIDAR sensor system 900 may include a scanner 740 configured to receive the emitted beam 735 from the transmitter 710, provide the emitted beam 735 to the environment, and receive a reflected beam 755 of the emitted beam 735 reflected from an object 702. The LIDAR sensor system 900 may include a grating coupler 725 and a grating coupler 730. The grating coupler 725 may receive a first component 770 of the reflected beam 755 with a first polarization 780. The grating coupler 730 may receive a second component 775 of the reflected beam 755 with a second polarization 785.

[0132] The first polarization 780 can be the same as the second polarization 785. The emission polarization 795 can be different from the first polarization 780 and the second polarization 785. For example, grating coupler 715 can output the emission beam 735 with emission polarization 795, and grating couplers 725 and 730 can receive the components 770 and 775 of the return beam 755 with polarizations 780 and 785, respectively, where polarizations 780 and 785 are orthogonal to emission polarization 795.

[0133] The LIDAR sensor system 900 may include a shifter 905. The transmitted beam 735 can pass through the shifter 905 unaffected. The shifter 905 may be a birefringent shifter, such that the shifter 905 has two different refractive indices (various features and examples of the shifter 905 will be further described herein). The shifter 905 may shift the return beam 755. For example, the shifter 905 may shift the return beam 755, which is polarized opposite to the transmitted beam 735, by a fixed amount. For example, the shifter 905 may shift the return beam 755 to the right of the transmitting antenna 810 during reception (e.g., relative to the orientation of the array during operation). The receiving antennas 825, 835 are aligned with the polarizations 780, 785 of the components 770, 775 of the return beam 755. The receiving antennas 825, 835 are located on either side of the shifted return beam 755 such that they compensate for the aforementioned focal plane drift at a specific target distance (e.g., the range from object 702 to scanner 740).

[0134] The LIDAR sensor system 900 may include an optical module 524 (e.g., a collimator 604 of the optical module 524). The collimator 604 may be located between the transmitter 710 and the scanner 740. The emitted beam 735 may pass through the collimator 604 unaffected. For example, the collimator 604 may be configured to provide the emitted beam 735 to the scanner 740. The collimator 604 may be configured to collimate the emitted beam 735. The collimator 604 may be configured to provide a collimated beam 910 to other components of the LIDAR sensor system 900, as described in more detail below. For example, the collimator 604 may be configured to provide a collimated beam 910 to the scanner 740.

[0135] The LIDAR sensor system 900 may include a waveplate 915. The waveplate 915 may be a quarter-wave plate. The emitted beam 735 can pass through the waveplate 915 unaffected. The waveplate 915 may induce circular polarization. For example, the waveplate 915 may cause the components 770, 775 of the returned beam 755 to be circularly polarized.

[0136] Figure 10 This is a block diagram illustrating an example of the optical components of System 1000. System 1000 may include components of the various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, System 1000 may be used to implement a single-polarization receiver and a switched local oscillator.

[0137] System 1000 is similar to System 800. However, the polarizations of the receiving antennas 825 and 835 are aligned with the polarization of the transmitting antenna 810. As described above, the transmitting antenna 810 may have the same polarization as the transmitting polarization 795, the receiving antenna 825 may have the same polarization as the first polarization 780, and the receiving antenna 835 may have the same polarization as the second polarization 785. In System 1000, the transmitting polarization 795 may be the same as polarizations 780 and 785, such that the transmitting antenna 810 may have the same polarization as the receiving antennas 825 and 835.

[0138] These receiving antennas 825, 835 can be located on either side of the transmitting antenna 810. For example, the receiving antennas 825, 835 and the transmitting antenna 810 can be positioned along the direction of focal plane drift, as described above. The physical proximity of the receiving antennas 825, 835 and the transmitting antenna 810 is selected to compensate for focal plane drift at a specific target distance (e.g., the range from object 702 to scanner 740).

[0139] Figure 11 It includes Figure 10A block diagram of an example of a LIDAR sensor system 1100 with optical components. The LIDAR sensor system 1100 can be combined with [other components] as shown in the reference diagrams. Figure 5 and 6 The LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 1100 can facilitate transmit-receive compensation, i.e., taking into account the time delay or other offset caused by the round-trip path of the emitted beam, which is output from the LIDAR sensor system 1100, reflected by an object, or otherwise scattered, and then returned as a return beam to the LIDAR sensor system 1100 for detection and processing, which could otherwise affect the characteristics of the LIDAR sensor system 1100, such as the signal-to-noise ratio.

[0140] Because system 1000 is similar to system 800, except that the polarization of the receiving antennas 825 and 835 is aligned with the polarization of the transmitting antenna 810, Figure 11 The block diagram depicted in Figure 9 The block diagram depicted is similar. However, since the polarizations of the receiving antennas 825 and 835 are not opposite to the polarization of the transmitting antenna 810, the shifter 905 can be omitted. For example, in the LIDAR sensor system 900, the shifter 905 can shift the return beam 755, which is polarized opposite to the transmitted beam 735, by a fixed amount. However, in the LIDAR sensor system 1100, when the polarizations 780, 785, and 795 are the same, the displacement of the return beam 755 is not required.

[0141] Figure 12 This is a block diagram illustrating an example of the optical components of system 1200. System 1200 may include components of the various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, system 1200 may be used to implement a single-polarization receiver and a switched local oscillator.

[0142] System 1200 is similar to System 800. However, mixers 840 and 845 communicate with two independent and balanced photodetectors, rather than with a single photodetector (e.g., receiver 712) having two photodiodes (e.g., grating couplers 725 and 730). Therefore, System 1200 may include receiver 1205, e.g., a second receiver. Receiver 1205 may include grating coupler 730. Receiver 712 may include grating coupler 725. Mixer 840 may provide signal 850 to receiver 712, similar to System 800. However, in System 1200, mixer 845 may provide signal 855 to receiver 1205.

[0143] In system 1200, local oscillator 815 can be passively separated between mixer 840 and mixer 845. For example, local oscillator 815 can actively switch the LO signal between mixer 840 and mixer 845 based on the scanning direction of scanner 740. For example, local oscillator 815 can transmit reference beam 820 (e.g., a first LO signal) to mixer 840. For example, local oscillator 815 can transmit reference beam 830, e.g., a second LO signal, to mixer 845.

[0144] Figure 13 This is a block diagram illustrating an example of the optical components of system 1300. System 1300 may include components of the various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, system 1300 may be used to implement a single-polarization receiver and a switched local oscillator.

[0145] System 1300 is similar to System 1000, such that shifter 905 can be omitted during operation. However, similar to System 1200, mixers 840, 845 communicate with two independent and balanced photodetectors instead of a single photodetector (e.g., receiver 712) having two photodiodes (e.g., grating couplers 725, 730). Therefore, System 1300 may include receiver 1205. Receiver 1205 may include grating coupler 730. Receiver 712 may include grating coupler 725. Similar to System 800, mixer 840 may provide signal 850 to receiver 712. However, in System 1300, mixer 845 may provide signal 855 to receiver 1205. Furthermore, similar to System 1200, local oscillator 815 may be passively decoupled between mixers 840 and 845.

[0146] Figure 14 This is a block diagram illustrating an example of the optical components of system 1400. System 1400 may include components of the various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, system 1400 may be used to implement a single-polarization receiver and a switched local oscillator.

[0147] System 1400 is a combination of System 800 and System 1000. Therefore, System 1400 may include two independent local oscillators. For example, System 1400 may include local oscillator 815 and local oscillator 1405 (e.g., a second local oscillator). The function of local oscillator 1405 may be similar to or the same as local oscillator 815. For example, local oscillator 1405 may output an LO signal. For example, local oscillator 1405 may actively switch the LO signal between at least two mixers based on the scanning direction of scanner 740. For example, local oscillator 1405 may output a third LO signal and a fourth LO signal. The LO signal may be similar to or the same as reference beam 512. For example, local oscillator 1405 may transmit a third LO signal, such as reference beam 1410. For example, local oscillator 1405 may transmit a fourth LO signal, such as reference beam 1420. By switching the LO signal using local oscillator 1405, the amount of power required by local oscillator 1405 can be reduced.

[0148] System 1400 may include receiving antenna 1415 and receiving antenna 1425. Receiving antennas 1415 and 1425 are similar to receiving antennas 825 and 835. For example, receiving antennas 1415 and 1425 may receive a returned beam 755, as described below.

[0149] System 1400 may include mixer 1430 and mixer 1435. Mixers 1430 and 1435 may be similar to or the same as mixers 840 and 845. Mixers 1430 and 1435 may receive signals, as described in more detail below. Mixer 1430 may output signal 1440, as described in more detail below. Mixer 1435 may output signal 1445, as described in more detail below.

[0150] Figure 15 It includes Figure 14 A block diagram of an example LIDAR sensor system 1500 with optical components. The LIDAR sensor system 1500 can be combined with [other components] as shown in the reference diagrams. Figure 5 and 6 The LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 1500 can facilitate transmit-receive compensation, i.e., taking into account the time delay or other offset caused by the round-trip path of the emitted beam, which is output from the LIDAR sensor system 1500, reflected by an object, or otherwise scattered, and then returned as a return beam to the LIDAR sensor system 1500 for detection and processing, which could otherwise affect the characteristics of the LIDAR sensor system 1500, such as the signal-to-noise ratio.

[0151] The LIDAR sensor system 1500 may include a displacement sensor 905 and a collimator 604, similar to... Figure 8 The system 800 is shown in the diagram. However, in system 1400, the LIDAR sensor system 1500 may include a waveplate 915. The waveplate 915 may be a quarter-wave plate. The emitted beam 735 can pass through the waveplate 915 unaffected. The waveplate 915 may induce circular polarization. For example, the waveplate 915 may cause the component of the returning beam 755 to be circularly polarized.

[0152] The LIDAR sensor system 1500 may include grating couplers 1510 and 1520. Grating couplers 1510 and 1520 may receive a return beam 755 provided by scanner 740. For example, grating coupler 1510 may receive a third component 1505 of the return beam 755 provided by scanner 740. For example, grating coupler 1520 may receive a fourth component 1525 of the return beam 755 provided by scanner 740. The third component 1505 of the return beam 755 may be in a third polarization 1515. The fourth component 1525 of the return beam 755 may be in a fourth polarization 1530.

[0153] As described above, the LIDAR sensor system 1500 may include a receiving antenna 1415 and a receiving antenna 1425 for the receiver 1205. The receiving antenna 1415 may be implemented by the grating coupler 1510 of the receiver 712. For example, the receiving antenna 1415 may be an optical antenna integrated onto the chip 705. The receiving antenna 1415 may couple a third component 1505 of the returned beam 755 from free space to the chip 705. The receiving antenna 1415 may be oriented relative to the surface on which the receiving antenna 1415 is disposed at an angle corresponding to the third polarization 1515 of the third component 1505 of the returned beam 755. The receiving antenna 1425 may be implemented by the grating coupler 1520 of the receiver 712. For example, the receiving antenna 1425 may be an optical antenna integrated onto the chip 705. The receiving antenna 1425 may couple a fourth component 1525 of the returned beam 755 from free space to the chip 705. The receiving antenna 1425 can be oriented relative to the surface where the receiving antenna 1425 is located at an angle corresponding to the fourth polarization 1530 of the fourth component 1525 of the returned beam 755.

[0154] Receiving antenna 1415 can receive the returned beam 755. For example, receiving antenna 1415 can receive the third component 1505 of the returned beam 755. Therefore, receiving antenna 1415 can be polarized with the same polarization orientation as the third component 1505 of the returned beam 755. For example, receiving antenna 1415 can have the same polarization as the third polarization 1515. Receiving antenna 1415 can provide the third component 1505 of the returned beam 755 to mixer 1430.

[0155] Receiving antenna 1425 can receive the returned beam 755. For example, receiving antenna 1425 can receive the fourth component 1525 of the returned beam 755. Therefore, receiving antenna 1425 can be oriented with the same polarization as the fourth component 1525 of the returned beam 755. For example, receiving antenna 1425 can have the same polarization as the fourth polarization 1530. Receiving antenna 1425 can provide the fourth component 1525 of the returned beam 755 to mixer 1435.

[0156] As described above, mixers 1430 and 1435 can receive signals. For example, mixer 1430 can receive reference beam 1410, such as a third LO signal. For example, mixer 1430 can receive the third component 1505 of the returned beam 755 from receiving antenna 1415. For example, mixer 1435 can receive reference beam 1420, such as a fourth LO signal. For example, mixer 1435 can receive the fourth component 1525 of the returned beam 755 from receiving antenna 1425.

[0157] As described above, mixers 1430 and 1435 can output signals. For example, the output signals can be based on signals received by each mixer 1430 and 1435 from receiving antennas 1415 and 1425, respectively. For example, the output signals can be based on signals received by each mixer 1430 and 1435 from local oscillator 1405. For example, mixers 1430 and 1435 can output signals in response to the return beam 755 and reference beams 1410 and 1420. For example, mixers 1430 and 1435 can mix the return beam 755 and reference beams 1410 and 1420, with each mixer outputting a signal.

[0158] Mixer 1430 can output signal 1440. Signal 1440 can be responsive to and based on the third component 1505 of the returned beam 755 and the reference beam 1410. Mixer 1435 can output signal 1445. Signal 1445 can be responsive to and based on the fourth component 1525 of the returned beam 755 and the reference beam 1420. Mixers 1430 and 1435 can provide signals 1440 and 1445 to two photodiodes (e.g., grating couplers 1510 and 1520), respectively. The two photodiodes can have two physically separate optical inputs, such that mixers 1430 and 1435 can provide signals 1440 and 1445 to a single photodetector. For example, mixers 1430 and 1435 can provide signals 1440 and 1445 to receiver 1205.

[0159] Figure 16This is a block diagram illustrating an example of the optical components of system 1600. System 1600 may include components of the various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, system 1600 may be used to implement a single-polarization receiver and a switched local oscillator.

[0160] System 1600 is similar to System 1400. However, similar to System 1200, mixers 1430 and 1435 communicate with two independent and balanced photodetectors, rather than with a single photodetector (e.g., receiver 1205). Therefore, System 1600 may include receiver 1605 (e.g., a third receiver) and receiver 1610 (e.g., a fourth receiver). Receiver 1605 may include grating coupler 1510. Receiver 1610 may include grating coupler 1520. Furthermore, receiver 712 may include grating coupler 725 and receiver 1205 may include grating coupler 730. Mixer 840 may provide signal 850 to receiver 712. Mixer 845 may provide signal 855 to receiver 1205. Mixer 1430 may provide signal 1440 to receiver 1605. Mixer 1435 may provide signal 1445 to receiver 1610.

[0161] 3.2 LiDAR sensor system including circulator

[0162] As described above, the LIDAR sensor system 500 can use various optical components to generate light, encode information on light, and output light for reflection or other scattering by objects in the environment surrounding the LIDAR sensor system 500. This can include, for example, the transmission of light through at least some of the components of the LIDAR sensor system 500 in free space, including in embodiments where light is provided by a laser source and modulated in frequency and / or phase using on-chip components, and then guided from the chip to scanning optics via collimating and / or circulator optics to be directed into the environment. Systems and methods according to this disclosure can implement various such components to perform free-space light transmission, maintain or improve the signal-to-noise ratio, and reduce the overall size of the circulator.

[0163] Figure 17A block diagram of a circulator 1700 is depicted, which can be implemented in various LIDAR sensor systems described herein, such as LIDAR sensor system 500 and optical module 524. The circulator 1700 can be implemented using chip 705. Chip 705 may include an emitter 710 and a grating coupler 715. The emitter 710 can output an emitted beam 735. The emitted beam 735 can be associated with polarization. For example, the emitted beam 735 can be associated with an emitted polarization 795. The emitter 710 can be located on chip 705. For example, the emitter 710 can be located on chip 705 and can output the emitted beam 735 outside the plane of chip 705.

[0164] Chip 705 may include receiver 712. Receiver 712 may include grating coupler 725. Grating coupler 725 may be spaced apart from transmitter 710 by a pitch 1720. The pitch 1720 between grating coupler 725 and transmitter 710 may be between about 8 micrometers and about 20 micrometers. The pitch 1720 between grating coupler 725 and transmitter 710 may be between about 12 micrometers and about 16 micrometers. For example, pitch 1720 may be 14 micrometers. Pitch 1720 may correspond to a time delay associated with a first target range for detecting object 702, as previously described. For example, grating coupler 725 is positioned such that grating coupler 725 is aligned with a translation caused by a time delay of the first component 770 of the returned beam 755. Receiver 712 may include grating coupler 730. Grating coupler 730 may be spaced apart from transmitter 710 by a pitch 1725. The spacing 1725 between the grating coupler 730 and the emitter 710 can be between approximately 30 micrometers and approximately 50 micrometers. The spacing 1725 between the grating coupler 730 and the emitter 710 can be between approximately 32 micrometers and approximately 36 micrometers. For example, the spacing 1725 can be 34 micrometers.

[0165] The circulator 1700 may include optics 532, such as one or more scanning optics. Optics 532 may have a scanning axis (e.g., reference axis). Figure 5 The optical device 532 rotates about the scanning axis (described as axis 534). The grating coupler 725 and grating coupler 730 can move along the scanning axis.

[0166] Circulator 1700 may be similar to or the same as circulator 528. Circulator 1700 includes waveplate 1730. Waveplate 1730 may be made of a birefringent material (e.g., quartz or plastic), for which the refractive index may differ for various light polarizations along at least one specific axis passing through the material. Waveplate 1730 may be located between emitter 710 and optics 532. Waveplate 1730 may be a half-wave plate. For example, when waveplate 1730 is a half-wave plate, waveplate 1730 may shift or rotate the polarization direction of linearly polarized light. Compared to the operation of waveplate 915, waveplate 1730 may rotate the emission polarization 795. For example, waveplate 1730 may rotate the emission polarization 795 by 45 degrees.

[0167] The circulator 1700 includes a displacement device 905. The displacement device 905 can be located between the waveplate 1730 and the optics 532. The displacement device 905 can be made of various materials, including but not limited to… The birefringent material is optically configured to control the path of light passing through the displacementr 905 based on the polarization of the light. The thickness of the displacementr 905 can be selected based on the target displacement amount and the type of material used for the displacementr 905.

[0168] For example, displacement device 905 can be made by The thickness of the displacement device 905 can be between approximately 0.5 mm and 0.7 mm. For example, the thickness of the displacement device 905 can be 0.6 mm. The displacement device 905 can shift the return beam 755. For example, when the return beam 755 provided by the object 702 contacts the displacement device 905, one of the two different refractive indices of the displacement device 905 can shift a portion of the return beam 755, for example, the second component 775.

[0169] The shifter 905 can shift the second component 775 of the returning beam 755. For example, the shifter 905 can shift the second component 775 of the returning beam 755 such that the second component 775 is between approximately 32 micrometers and approximately 36 micrometers away from the rotated emitted beam 1715. For example, the shifter 905 can shift the second component 775 of the returning beam 755 such that the second component 775 is 34 micrometers away from the rotated emitted beam 1715. For example, the shifter 905 can shift the second component 775 of the returning beam 755 between approximately 18 micrometers and approximately 22 micrometers. For example, the shifter 905 can shift the second component 775 of the returning beam 755 by 20 micrometers. For example, the shifter 905 can shift the second component 775 of the returning beam 755 by 20 micrometers such that the second component 775 is 20 micrometers away from the first component 770 of the returning beam 755. Therefore, since the second component 775 of the returned beam 755 is shifted by approximately 18 and 22 micrometers, the spacing 1725 between the grating coupler 730 and the transmitter 710 allows the grating coupler 730 to be positioned to receive the second component 775 of the returned beam 755. For example, the spacing 1725 between the grating coupler 730 and the transmitter 710 corresponds to the time delay and the displacement of the second component 775 relative to the first component 770 performed by the circulator 1700.

[0170] The circulator 1700 may include a waveplate 1735. The waveplate 1735 may be located between the shifter 905 and the optics 532. The waveplate 1735 may be used to address the change in polarization of the rotating emitted beam 1715 relative to the target polarization.

[0171] The circulator 1700 can guide the emitted beam 735 to the optics 532. For example, the circulator 1700 can guide the emitted beam 735 to the optics 532 in a direction parallel to the plane of the chip 705. For example, the optics 532 can be tilted relative to the plane of the chip 705, for example, at an angle greater than about 8 degrees, to reduce back reflections relative to light passing through the free space around the circulator 1700; the grating coupler 715 can be angled, for example, at least about 12 degrees, so that the optics 532 can be positioned parallel to the chip 705. Positioning the optics 532 parallel to the plane of the chip 705—for example, the plane of the chip 706—can simplify mounting. For example, parallel mechanical mounting of the optics 532 relative to the chip 705 can facilitate manufacturing, such as by allowing the optics 532 and / or the circulator 1700 to be directly coupled (e.g., glued) to the chip 705.

[0172] The circulator 1700 can receive the emitted beam 735 and provide the emitted beam 735 to the optics 532. For example, the emitted beam 735 can pass through the waveplate 1730 and the shifter 905 and contact the optics 532. The circulator 1700 can receive the returned beam 755 reflected from the emitted beam 735 by the object 702. For example, the returned beam 755 can contact the shifter 905. The circulator 1700 can split the returned beam 755 into at least a first component 770 and a second component 775. For example, the circulator 1700 can split the returned beam 755 into at least a first component 770 and a second component 775 via the shifter 905, as described above. The circulator 1700 can provide the first component 770 to the grating coupler 725 and the second component 775 to the grating coupler 730. For example, the first component 770 and the second component 775 can pass through the waveplate 1730 to reach the grating coupler 725 and the grating coupler 730, respectively.

[0173] The circulator 1700 can rotate the emitted beam 735 and provide the rotated emitted beam 1715 to the optics 532. For example, the emitted beam 735 can contact the waveplate 1730, and the waveplate 1730 can rotate the emitted beam 735. The waveplate 1730 can provide the rotated emitted beam 1715 to the displacement 905. The rotated emitted beam 1715 can pass through the displacement 905 unaffected and contact the optics 532.

[0174] The circulator 1700 can polarize the first component 770 of the returned beam 755. For example, the returned beam 755 can return from the object 702 unpolarized. The returned beam 755 can contact the displacement device 905. The displacement device 905 can rotate (e.g., polarize) the first component 770 of the returned beam 755 such that the polarization associated with the first component 770 corresponds to the polarization of the rotated emitted beam 1715. The first component 770 of the returned beam 755 can contact the waveplate 1730. The waveplate 1730 can rotate (e.g., polarize) the first component 770 of the returned beam 755 to provide a first component 770 at a first polarization 780. The waveplate 1730 can rotate (e.g., polarize) the first component 770 of the returned beam 755 such that the first polarization 780 associated with the first component 770 corresponds to the emitted polarization 795 associated with the emitted beam 735. For example, the waveplate 1730 can rotate the first component 770 of the returned beam 755 by 45 degrees.

[0175] The circulator 1700 can polarize the second component 775 of the returned beam 755. For example, the returned beam 755 can return from the object 702 unpolarized. The returned beam 755 can contact the shifter 905. The shifter 905 can shift the second component 775 of the returned beam 755 as described above. The shifter 905 can rotate (e.g., polarize) the second component 775 of the returned beam 755 such that the polarization associated with the second component 775 is orthogonal to the polarization of the rotated emitted beam 1715. The second component 775 of the returned beam 755 can contact the waveplate 1730. The waveplate 1730 can rotate (e.g., polarize) the second component 775 of the returned beam 755 to provide the second component 775 at a second polarization 785. The waveplate 1730 can rotate (e.g., polarize) the second component 775 of the returned beam 755 such that the second polarization 785 associated with the second component 775 is orthogonal to the emitted polarization 795 associated with the emitted beam 735. For example, waveplate 1730 can rotate the second component 775 of the returning beam 755 by 45 degrees. Since the polarization of the second component 775 is orthogonal to the first component 770 before the second component 775 and the first component 770 come into contact with waveplate 1730, waveplate 1730 can rotate the second component 775 and the first component 770 by 45 degrees in the same direction as the mutually orthogonal first polarization 780 and second polarization 785, respectively.

[0176] The circulator 1700 can provide a first component 770 of the return beam 755 having a first polarization 780 to the grating coupler 725. The circulator 1700 can provide a second component 775 of the return beam 755 having a second polarization 785 to the grating coupler 730. As described above, the grating coupler 725 and the grating coupler 730 can be rotated to correspond to the first polarization 780 and the second polarization 785, respectively, so as to effectively align with components 770, 775. The grating coupler 725 can receive at least a first threshold amount of the first component 770 of the return beam 755 (e.g., greater than about 30 percent; between about 30 percent and about 90 percent; between about 50 percent and about 80 percent). For example, the first threshold amount can correspond to the amount required by the output signal (e.g., signal 850) of the grating coupler 725. The grating coupler 730 can receive at least a second threshold amount (e.g., greater than about 30 percent; between about 30 percent and about 90 percent; between about 50 percent and about 80 percent) of the second component 775 of the returned beam 755. For example, the second threshold amount can correspond to the amount required for the output signal (e.g., signal 855) of the grating coupler 730.

[0177] Some illustrative embodiments have now been described. It is clear that the foregoing is illustrative and not limiting, and has been presented by way of example. Specifically, while many of the examples presented herein relate to specific combinations of methodological behaviors or system elements, these behaviors and elements can be combined in other ways to achieve the same objective. The behaviors, elements, and features discussed in connection with one embodiment are not intended to exclude similar roles in other embodiments.

[0178] The wording and terminology used herein are for descriptive purposes and should not be considered limiting. The use of “comprising,” “including,” “having,” “containing,” “involving,” “characterized as,” “characterized in,” and variations thereof is intended to cover items subsequently listed, their equivalents and additional items, and alternative implementations consisting only of the items subsequently listed. In one implementation, the systems and methods described herein consist of one of the said elements, behaviors, or components, a combination of multiple said elements, behaviors, or components, or all of said elements, behaviors, or components.

[0179] Any reference to an implementation, element, or behavior of a system or method mentioned herein in the singular may also cover implementations that include multiple such elements, and any reference herein in the plural may also cover implementations that include only a single element. References in the singular or plural form are not intended to limit the currently disclosed systems or methods, their components, behaviors, or elements to a single or plural configuration. A reference to any behavior or element based on any information, behavior, or element may include an implementation in which such behavior or element is at least in part based on any information, behavior, or element.

[0180] Any implementation disclosed herein may be combined with any other implementation or embodiment, and references to "implementation," "some implementations," "an implementation," etc., are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation or embodiment. These terms used herein do not necessarily refer to the same implementation. Any implementation may be combined with any other implementation (including exclusively) in any manner consistent with the aspects and implementations disclosed herein.

[0181] When a reference numeral follows a technical feature in an accompanying drawing, detailed description, or any claim, that reference numeral is included to enhance the comprehensibility of the drawing, detailed description, and claims. Therefore, the reference numeral, or its absence, does not have any limiting effect on the scope of any claim element.

[0182] The systems and methods described herein may be embodied in other specific forms without departing from their characteristics. Further descriptions of relative parallel, perpendicular, vertical, or other positioning or orientation include variations within + / -10% or + / -10 degrees of purely vertical, parallel, or perpendicular positioning. Unless expressly stated otherwise, references to "approximately," "about," "substantially," or other terms of degree include variations within + / -10% relative to a given measurement, unit, or range. Coupling elements may be electrically, mechanically, or physically coupled to each other, directly or through intermediate elements. Therefore, the scope of the systems and methods described herein is indicated by the appended claims rather than the foregoing description, and variations in the meaning and scope of equivalent content belonging to the claims are encompassed therein.

[0183] The term "coupling" and its variations refer to the connection of two components directly or indirectly to each other. This connection can be fixed (e.g., permanent or fixed) or movable (e.g., detachable or releasable). This connection can be achieved by: two components directly coupled or mutually coupled; two components mutually coupled using a separate intermediate component and any other intermediate component coupled to each other; or two components mutually coupled using an intermediate component that is integrally formed with one of the two components into a single whole. If "coupling" or its variations are modified by an additional term (e.g., direct coupling), the general definition of "coupling" provided above will be modified by the common linguistic meaning of the additional term (e.g., "direct coupling" means the connection of two components without any separate intermediate component), resulting in a narrower definition than the general definition of "coupling" provided above. This coupling can be mechanical, electrical, or fluid.

[0184] References to "or" can be interpreted as inclusive, and therefore any term described using "or" can refer to a single, multiple, or all of the stated terms. A reference to "at least one of 'A' and 'B'" can include only 'A', only 'B', or both 'A' and 'B'. Such references used in conjunction with "include" or other open terms can include additional items.

[0185] Modifications can be made to the components and behaviors described herein, such as variations in the size, dimensions, structure, shape and proportion, parameter values, installation arrangement, material use, color, and orientation of various components, without substantially departing from the teachings and advantages of the subject matter disclosed herein. For example, an element shown as a single unit may be composed of multiple parts or components, the positions of the components may be reversed or otherwise changed, and the nature or number of discrete components or positions may be altered or varied. Other substitutions, modifications, alterations, and omissions can also be made in the design, operating conditions, and arrangement of the disclosed components and operations without departing from the scope of this disclosure.

[0186] References to the location of elements herein (e.g., “top,” “bottom,” “above,” “below”) are used only to describe the orientation of the various elements in the figures. It should be noted that the orientation of the various elements may differ according to other exemplary embodiments, and such variations are intended to be included in this disclosure.

Claims

1. A LiDAR sensor system for light detection and ranging in vehicles, comprising: A transmitter configured to output a emitted beam; Receiver, including: First receiving grating coupler; and Second receiving grating coupler; One or more scanning optics; and A looper, the looper being configured to: Receive the emitted light beam and provide the emitted light beam to the one or more scanning optical devices; Receive the returned beam of the emitted beam reflected by the object; The returned beam is divided into at least a first component and a second component; and The first component is provided to the first receiving grating coupler and the second component is provided to the second receiving grating coupler.

2. The LIDAR sensor system according to claim 1, wherein, The emitted beam is polarized, and the circulator is further configured to: The polarization of the emitted beam is rotated and the rotated emitted beam is provided to the one or more scanning optics; The first component of the returned beam is polarized such that the polarization of the first component corresponds to the polarization of the emitted beam; The second component of the returned beam is polarized such that its polarization is orthogonal to the polarization of the emitted beam; and The polarization of the first and second components of the returned beam is rotated by 45 degrees to provide the rotated first component to the first receiving grating coupler and the rotated second component to the second receiving grating coupler.

3. The LIDAR sensor system according to claim 1, wherein, The circulator includes: A half-wave plate located between the transmitter and the one or more scanning optics; and A displacement device located between the half-wave plate and the one or more scanning optics.

4. The LIDAR sensor system according to claim 1, wherein, The circulator includes: A first half-wave plate located between the transmitter and the one or more scanning optics; A displacement device located between the half-wave plate and the one or more scanning optics; and A second half-wave plate located between the displacement device and the one or more scanning optics.

5. The LIDAR sensor system according to claim 1, wherein: The distance between the first receiving grating coupler and the transmitter is between approximately 8 micrometers and approximately 20 micrometers; and The distance between the second receiving grating coupler and the transmitter is between approximately 30 micrometers and approximately 50 micrometers.

6. The LIDAR sensor system according to claim 1, wherein: The distance between the first receiving grating coupler and the transmitter is a first distance, which corresponds to a time delay associated with the target distance for detecting the object; and The distance between the second receiving grating coupler and the transmitter is a second distance, which corresponds to the time delay and the displacement of the second component relative to the first component through the circulator.

7. The LIDAR sensor system according to claim 1, wherein: The one or more scanning optics have a scanning axis, and the one or more scanning optics rotate relative to the scanning axis; and The first receiving grating coupler and the second receiving grating coupler are positioned along the scanning axis.

8. The LIDAR sensor system according to claim 1, wherein: The first receiving grating coupler receives at least about fifty percent of the first component of the returned beam; and The second receiving grating coupler receives at least about fifty percent of the second component of the returned beam.

9. The LIDAR sensor system according to claim 1, wherein, The circulator includes a displacement device configured to shift the second component of the returned beam relative to the first component of the returned beam, the displacement device being made of a birefringent material.

10. The LIDAR sensor system according to claim 1, wherein, The circulator includes: A displacement device made of LiNbO3 with a thickness between about 0.53 mm and about 0.65 mm is located between the transmitter and the one or more scanning optics and is configured to shift the second component of the returned beam between about 18 and about 22 micrometers.

11. The LIDAR sensor system according to claim 1, wherein, The transmitter is located on the chip and is configured to output the emitted beam at an angle to the plane of the chip.

12. The LIDAR sensor system according to claim 11, wherein, The circulator is configured to guide the emitted beam in a direction parallel to the plane to the one or more scanning optics.

13. An autonomous vehicle control system, comprising: A transmitter configured to output a emitted beam; The receiver includes a first receiving grating coupler and a second receiving grating coupler; Scanner; A looper, the looper being configured to: Receive the emitted beam and guide the emitted beam to the scanner; Receive the returned beam of the emitted beam reflected by the object; The returned beam is divided into at least a first component and a second component; as well as The first component is directed to the first receiving grating coupler and the second component is directed to the second receiving grating coupler; as well as One or more processors, said one or more processors being configured to: Determine at least one of the distance to the object or the velocity of the object based on the first component and the second component; as well as The operation of the autonomous vehicle is controlled in response to at least one of the distance or the speed.

14. The autonomous vehicle control system of claim 13, further comprising a modulator configured to apply at least one of frequency modulation or phase modulation to a beam output by the transmitter as the transmitted beam.

15. The automated driving vehicle control system according to claim 13, wherein, The emitted beam is polarized, and the circulator is further configured to: The polarization of the emitted beam is rotated and the rotated emitted beam is provided to the scanner; The first component of the returned beam is polarized such that the polarization of the first component corresponds to the polarization of the emitted beam; The second component of the returned beam is polarized such that the polarization of the second component is orthogonal to the polarization of the emitted beam; as well as The polarization of the first and second components of the returned beam is rotated by 45 degrees to provide the rotated first component to the first receiving grating coupler and the rotated second component to the second receiving grating coupler.

16. The automated vehicle control system according to claim 13, wherein: The distance between the first receiving grating coupler and the transmitter is a first distance, which corresponds to a time delay associated with the target distance for detecting the object; and The distance between the second receiving grating coupler and the transmitter is a second distance, which corresponds to the time delay and the displacement of the second component relative to the first component through the circulator.

17. The automated vehicle control system according to claim 13, wherein: The first receiving grating coupler receives at least about fifty percent of the first component of the returned beam; and The second receiving grating coupler receives at least about fifty percent of the second component of the returned beam.

18. An autonomous vehicle, comprising: LIDAR sensor systems include: An emission grating coupler, configured to output an emission beam; First receiving grating coupler; Second receiving grating coupler; Scanner; and A looper, the looper being configured to: Receive the emitted beam and provide the emitted beam to the scanner; Receive the returned beam of the emitted beam reflected by the object; The returned beam is divided into at least a first component and a second component; and The first component is directed to the first receiving grating coupler and the second component is directed to the second receiving grating coupler; Steering system; Braking system; and A vehicle controller, comprising one or more processors, the one or more processors being configured to: The first component and the second component are used to determine at least one of the distance to the object or the velocity of the object; and The operation of at least one of the steering system and the braking system is controlled in response to at least one of the distance or the speed.

19. The autonomous vehicle according to claim 18, wherein, The emitted beam is polarized, and the circulator is further configured to: The polarization of the emitted beam is rotated and the rotated emitted beam is provided to the scanner; The first component of the returned beam is polarized such that the polarization of the first component corresponds to the polarization of the emitted beam; The second component of the returned beam is polarized such that the polarization of the second component is orthogonal to the polarization of the emitted beam; as well as The polarization of the first and second components of the returned beam is rotated by 45 degrees to provide the rotated first component to the first receiving grating coupler and the rotated second component to the second receiving grating coupler.

20. The autonomous vehicle according to claim 18, wherein: The first receiving grating coupler receives at least about fifty percent of the first component of the returned beam; and The second receiving grating coupler receives at least about fifty percent of the second component of the returned beam.

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