LIDAR sensor system

Abstract

A light detection and ranging (LIDAR) system for a vehicle includes a transmitter, a receiver, one or more scanning optics, and an optical module. The emitter is configured to output an emission beam. The receiver comprises a first receiving grating coupler and a second receiving grating coupler. The optical module is configured to receive the emitted beam and provide the emitted beam to the one or more scanning optics, receive a return beam reflecting the emitted beam by the object, split the return beam into at least a first component and a second component, the first component is directed to a first receiving grating coupler and the second component is directed to a second receiving grating coupler.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

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

[0003] Optical detection of range using lasers, often referred to by the mnemonic LIDAR (standing for "light detection and ranging") and sometimes referred to as "RADAR"), is used for a variety of applications, including imaging and collision avoidance. LIDAR provides finer-scale range resolution at a smaller beam size than traditional microwave ranging systems such as radio wave detection and ranging (RADAR). Summary of the invention

[0004] At least one aspect relates to a light detection and ranging (LIDAR) system, such as a LIDAR sensor system for a vehicle. The LIDAR system includes a transmitter configured to output a transmission 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 optical devices. The LIDAR system includes a circulator. The circulator is configured to receive the transmission beam and direct the transmission beam to the one or more scanning optical devices, receive a return beam of the transmission beam reflected by 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 direct 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 optical devices, a circulator, and one or more processors. The transmitter is configured to output a transmission light beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The circulator is configured to receive the transmission light beam and direct the transmission light beam to one or more scanning optical devices, receive a return light beam reflected by the object, split the return light beam into at least a first component and a second component, and direct the first component to the first receiving grating coupler and direct the second component to the second receiving grating coupler. The one or more processors are configured to determine at least one of a range to an object or a speed of the object based on the first component and the second component, and control the operation of the autonomous vehicle in response to at least one of the range or the speed.

[0006] At least one aspect relates to an autonomous vehicle. The autonomous vehicle includes a LIDAR system, which includes a transmitter, a receiver, one or more scanning optical devices and a circulator. The transmitter is configured to output a transmission beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The circulator is configured to receive the transmission beam and direct the transmission beam to one or more scanning optical devices, receive a return beam of the transmission beam reflected by 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 direct 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, which are configured to determine at least one of a distance to an object or a speed of the object based on the first component and the second component, and control the operation of the autonomous vehicle in response to at least one of the distance or the speed.

[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 a transmission light beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The optical module is configured to receive a return light beam reflected by an object from the transmission light beam, and provide a first component of the return light beam to the first receiving grating coupler and provide a second component of the return light beam to the second receiving grating coupler.

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

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

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

[0011] In some embodiments, the transmitter includes at least one transmitting grating coupler.

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

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

[0014] In some embodiments, the optical module includes a collimator configured to collimate the emission light beam.

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

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

[0017] In some implementations, the first receive grating coupler receives at least about fifty percent of the first component of the returned light beam, and the second receive grating coupler receives at least about fifty percent of the second component of the returned light beam.

[0018] In some embodiments, the optical module includes The displacer is formed to have a thickness between about 0.53 mm and about 0.65 mm. The displacer can be located between the emitter and one or more scanning optics and is configured to displace the second component of the return beam between about 18 microns and about 22 microns.

[0019] In some embodiments, the emitter is located on the chip and is configured to output an emission light beam at an angle to the plane of the chip.

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

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

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

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

[0024] At least one aspect relates to an autonomous vehicle, which includes 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 a transmitting light beam, a first receiving grating coupler, a second receiving grating coupler, and an optical module, the optical module being configured to receive a return light beam reflected by an object, and directing a first component of the return light beam to the first receiving grating coupler and directing a second component of the return light beam to the second receiving grating coupler. The vehicle controller includes one or more processors configured to determine at least one of a distance to an object or a speed of the object using the first component and the second component, and to control the operation of at least one of a steering system or a braking system in response to at least one of the distance or the speed.

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

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

[0027] Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be limiting in any way. Any feature described herein may be used with any other feature, and any subset of such features may be used in combination according to various embodiments. Other aspects, inventive features, and advantages of the devices and / or processes described herein (defined solely by the claims) will become apparent in the detailed description set forth herein and given in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments are illustrated by way of example and not limitation in the accompanying drawings, in which like reference numerals indicate similar elements, and in which:

[0029] Figure 1 is a block diagram of an example system environment for an autonomous vehicle;

[0030] Figure 2 is a block diagram of an example system environment for an autonomous commercial truck vehicle;

[0031] Figure 3 is a block diagram of an example system environment for an autonomous commercial truck vehicle;

[0032] Figure 4 is a block diagram of an example system environment for an autonomous commercial truck vehicle;

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

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

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

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

[0037] Fig. 9 Yes Figure 8 A block diagram of an example LIDAR sensor system of an optical component;

[0038] Fig.10 is a block diagram of an example of the optical components of the system;

[0039] Fig.11 Yes Fig.10 A block diagram of an example LIDAR sensor system of an optical component;

[0040] Fig.12 is a block diagram of an example of the optical components of the system;

[0041] Fig.13 is a block diagram of an example of the optical components of the system;

[0042] Fig.14 is a block diagram of an example of the optical components of the system;

[0043] Fig.15 Yes Fig.14 A block diagram of an example LIDAR sensor system of an optical component;

[0044] Fig.16 is a block diagram of an example of optical components of the system; and

[0045] Fig.17 is a block diagram of a circulator example. DETAILED DESCRIPTION

[0046] The LIDAR sensor system can generate and transmit a light beam that can be reflected or otherwise scattered by an object into a return light beam that corresponds to the transmitted light beam. The LIDAR sensor system can receive the return light beam and process the return light beam or its characteristics to determine parameters about the object, such as range and speed. The LIDAR sensor system can apply various frequency or phase modulations to the transmitted light beam, which can help to correlate the return light beam with the transmitted light beam to determine parameters about the object.

[0047] The LIDAR sensor system may include a transmitter, a receiver, one or more scanning optical devices, and a circulator. The transmitter is configured to output a transmission beam. The receiver includes a first receiving grating coupler and a second receiving grating coupler. The circulator is configured to receive the transmission beam and direct the transmission beam to one or more scanning optical devices, receive a return beam of the transmission beam reflected by the object, separate 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 direct the second component to the second receiving grating coupler. One or more scanning optical devices may include a mirror to output a transmission beam, which can be scanned over a field of view to be reflected by an object or otherwise scattered as a return beam, which can be used to determine distance, velocity, and Doppler information about the object, such as for controlling the operation of an autonomous vehicle.

[0048] Systems and methods according to the present disclosure can implement a LIDAR sensor system in which the circulator design is assembled with the receiving grating coupler along the mechanical scanning axis rather than along the transmitting array axis. This arrangement simplifies the 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 return beam without affecting the direction of the return beam. Therefore, the radiation from the grating coupler can have an angle greater than the tilt of the circulator optics, which improves processing efficiency. For example, this enables the circulator optics to be mounted in parallel with the integrated chip where the transmitter and receiver are located. However, the advantages of the above-mentioned integrated chips are not limited to autonomous vehicles. They are beneficial for any type of vehicle equipped with a LIDAR sensor.

[0049] 1. System environment of autonomous vehicles

[0050] Figure 1is a block diagram illustrating an example of a system environment for an autonomous vehicle according to some embodiments. Figure 1 An example autonomous vehicle 100 is depicted in which various techniques disclosed herein may be implemented. For example, the vehicle 100 may include a powertrain 102 including a prime mover 104 powered by an energy source 106 and capable of providing power to a transmission assembly 108; and a control system 110 including a directional control 112, a powertrain control 114, and a brake control 116. The vehicle 100 may be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or cargo and capable of traveling in a variety of environments. The above-described components 102-116 can vary widely depending on the type of vehicle in which they are used (such as a wheeled land vehicle, such as a car, van, truck, or bus). The prime mover 104 may include one or more electric motors and / or internal combustion engines (among others). The energy source may include, for example, a fuel system (e.g., providing gasoline, diesel, hydrogen, etc.), a battery system, solar panels or other renewable energy sources, and / or a fuel cell system. The drivetrain 108 may include wheels and / or tires and a transmission and / or any other mechanical drive assembly to convert the output of the prime mover 104 into vehicle motion; and one or more brakes configured to controllably stop or slow the speed of the vehicle 100 and a direction or steering assembly suitable for controlling the trajectory of the vehicle 100 (e.g., a rack and pinion steering linkage that enables 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 longitudinal axis of the vehicle). In some embodiments, a combination of powertrains and energy sources may be used (e.g., in the case of an electric / gas hybrid vehicle), and in some cases, multiple electric machines (e.g., dedicated to individual wheels or axles) may be used as prime movers.

[0051] The direction control 112 may include one or more actuators and / or sensors for controlling and receiving feedback from a direction or steering assembly to enable the vehicle 100 to follow a desired trajectory. The powertrain control 114 may be configured to control the output of the powertrain 102, for example, controlling the output power of the prime mover 104, controlling the gear of the transmission in the transmission assembly 108, etc., thereby controlling the speed and / or direction of the vehicle 100. The brake control 116 may be configured to control one or more brakes that slow or stop the vehicle 100, for example, 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, construction equipment, may use different powertrains, transmissions, energy sources, directional control, powertrain control, and brake controls. In addition, in some embodiments, some components may be combined, for example, the directional control of the vehicle is primarily handled by changing the output of one or more prime movers.

[0053] Various levels of automated driving control of the vehicle 100 may be implemented in a 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 ("GPUs") and / or one or more central processing units ("CPUs").

[0054] The sensor 130 may include various sensors suitable for collecting information from the vehicle's surroundings for controlling vehicle operation. For example, the sensor 130 may include a radar sensor 134, a LIDAR (light detection and ranging) sensor 136, a 3D positioning sensor 138, and the 3D positioning sensor 138, for example, an accelerometer, a gyroscope, a magnetometer, or any one of a satellite navigation system (such as GPS (Global Positioning System), GLONASS (Globalnaya Navigazionnaya Sputnikovaya Sistema, or Global Navigation Satellite System), Beidou Navigation Satellite System (BDS), Galileo, compass, etc.). The 3D positioning sensor 138 can be used to determine the position of the vehicle on the earth using satellite signals. The sensor 130 may include a camera 140 and / or an IMU (Inertial Measurement Unit) 142. The camera 140 may be a single or stereo camera and may record static and / or video images. The 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, may be used to monitor the rotation of one or more wheels of the vehicle 100. Each sensor 130 may output sensor data at various data rates, which may be different from the data rates of the other sensors 130.

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

[0056] Can be used Figure 1 Multiple sensors of the type shown in can be used to achieve redundancy and / or cover different areas around the vehicle, and other types of sensors can 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 can be implemented using the same processor and / or memory in some cases. The subsystem can be implemented at least in part using various dedicated circuit logic, various processors, various field programmable gate arrays ("FPGA"), various application-specific integrated circuits ("ASIC"), various real-time controllers, etc. As described above, multiple subsystems can utilize circuits, processors, sensors and / or other components. In addition, the various components in the vehicle control system 120 can be networked in various ways.

[0057] In some embodiments, the vehicle 100 may also include an auxiliary vehicle control system (not shown) that may be used as a redundant or backup control system for the 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 in the 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 the 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] Various architectures (including various combinations of software, hardware, circuit logic, sensors, and networks) can be used to implement Figure 1 . 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 as well as any supplementary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), read-only memory, etc. In addition, each memory may be considered to include: memory storage physically located elsewhere in the vehicle 100, such as any cache memory in a processor; and any storage capacity used as virtual memory, such as stored on a mass storage device or another computer controller. Figure 1 One or more of the processors shown in the figure or a completely separate processor can be used to implement additional functions in the vehicle 100 in addition to the purpose of autonomous driving control, such as controlling the entertainment system, operating doors, lights, convenience functions, etc.

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

[0060] Additionally, the vehicle 100 may include a user interface 164 to enable the vehicle 100 to receive a plurality of inputs from and generate outputs for a user or operator, such as one or more displays, touch screens, voice and / or gesture interfaces, buttons and other tactile controls, etc. Otherwise, the 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] In addition, the vehicle 100 may include one or more network interfaces, such as a network interface 162, which is suitable for communicating with one or more networks 170 (e.g., a local area network ("LAN"), a wide area network ("WAN"), a 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 the vehicle 100 receives environmental and other data for its autonomous driving control. Data collected by one or more sensors 130 may be uploaded to a computing system 172 via the network 170 for additional processing. In some embodiments, a timestamp may be added to each instance of vehicle data prior to upload.

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

[0063] In general, routines executed to implement the various embodiments described herein, whether implemented as part of an operating system or 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 the steps required to perform the steps or elements embodying various aspects of the present disclosure. In addition, while the 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 that the embodiments 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-transitory media such as volatile and nonvolatile memory devices, floppy disks and other removable disks, solid-state drives, hard drives, magnetic tapes, and optical disks (e.g., CD-ROMs, DVDs, etc.), and the like.

[0065] In addition, the various program codes described below can be identified based on the application in which it is implemented in a specific embodiment. Any specific program nomenclature below is used for convenience only, and thus the present disclosure should not be limited to use only in any specific application identified and / or implied by the nomenclature. In addition, given the generally endless ways in which computer programs can be organized into routines, processes, methods, modules, objects, etc., and the various ways in which program functions can be distributed between various software layers (e.g., operating systems, libraries, APIs, applications, applets, etc.) residing within a typical computer, the present disclosure is not limited to the specific organization and distribution of program functions described herein.

[0066] 2. LIDAR for automotive applications

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

[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 striking the object back to the sensor of the FM or PM LIDAR sensor system (e.g., Figure 1 In other cases, an object (e.g., a shiny road sign) may have a high reflectivity (e.g., greater than 10%) because it reflects a significant amount of light striking the object back toward the sensor of the FM LIDAR sensor system.

[0069] Regardless of the reflectivity of the object, the FM LIDAR sensor system is capable of detecting (e.g., classifying, identifying, finding, etc.) an object at a greater distance (e.g., 2 times) than a conventional LIDAR sensor system. For example, the FM LIDAR sensor system can detect a low reflectivity object at a distance of 300 meters, and a high reflectivity object at a distance of 400 meters.

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

[0071] Therefore, by detecting objects at a greater distance, the FM LIDAR sensor system 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 truck vehicles) traveling at highway speeds.

[0072] FM LIDAR sensor systems can provide accurate velocity for each data point instantly. In some embodiments, velocity measurement is achieved using the Doppler effect, which shifts 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 the laser signal. For example, for speeds encountered on roads with speeds less than 100 meters per second (m / s), this shift at a wavelength of 1550 nanometers (nm) is equivalent to a frequency shift of less than 130 megahertz (MHz). This frequency shift is small and therefore difficult to detect directly in the optical domain. However, by using coherent detection in an FMCW, PMCW, or FMQW LIDAR sensor system, the signal can be converted to the RF domain so that the frequency shift can be calculated using various signal processing techniques. This enables the autonomous vehicle control system to process incoming data more quickly.

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

[0074] Faster identification and / or tracking by the FM LIDAR sensor system gives the autonomous vehicle control system more time to maneuver the vehicle. Better knowledge of how fast the object is moving also allows the autonomous vehicle control system to plan a better response.

[0075] FM LIDAR sensor systems can have less static than traditional LIDAR sensor systems. That is, traditional LIDAR sensor systems, which are designed to be more sensitive to light, typically do not perform well 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 shortcomings, 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 issues because each sensor is specifically designed to respond only to its own light characteristics (e.g., light beam, light wave, light pulse). If the returned light does not match the timing, frequency, and / or wavelength of the originally emitted light, the FM sensor can filter out (e.g., remove, ignore, etc.) that data point. As a result, FM LIDAR sensor systems produce (e.g., generate, derive, etc.) more accurate data with fewer hardware or software requirements, resulting in smoother driving.

[0077] FM LIDAR sensor systems are more scalable than traditional LIDAR sensor systems. As more and more autonomous vehicles (e.g., cars, commercial trucks, etc.) appear on the road, vehicles driven by FM LIDAR sensor systems may not have to deal with interference issues caused by sensor crosstalk. In addition, FM LIDAR sensor systems use less peak power of light than traditional LIDAR sensors. Therefore, some or all of the optical components of FM LIDAR can be produced on a single chip, which has its own benefits, as described in this article.

[0078] 2.1 Commercial Trucks

[0079] Figure 21 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, 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 plurality of modes of transportation to move cargo), and / or any other road-based freight application. In some embodiments, 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 moving truck, etc. In some embodiments, cargo 106B may be cargo and / or agricultural products. In some embodiments, commercial truck 102B may include a trailer for carrying cargo 106B, such as a flatbed trailer, a low bed trailer, a step trailer, an expandable flatbed trailer, a side kit trailer, etc.

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

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

[0082] As shown, the LIDAR sensor system 104B in the environment 100B may be configured to detect objects (eg, another vehicle, a bicycle, a tree, a road sign, a pothole, etc.) that are at a relatively close distance (eg, 30 meters or less) from the commercial truck 102B.

[0083] Figure 31 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 included in environment 100B (eg, commercial truck 102B, cargo 106B, LIDAR sensor system 104B, etc.).

[0084] Environment 100C includes object 110C (in Figure 3 As shown, the LIDAR sensor system 104B in the environment 100C can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) that are a certain distance (e.g., 100 meters) from the commercial truck 102B.

[0085] Figure 4 1 is a block diagram illustrating an example of a system environment for autonomous commercial truck vehicles according to some embodiments. Environment 100D includes the same components included in environment 100B (e.g., commercial truck 102B, cargo 106B, LIDAR sensor system 104B, etc.).

[0086] Environment 100D includes objects 110D (in Figure 4 As shown, the LIDAR sensor system 104B in the environment 100D can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) that are within a certain distance (e.g., 300 meters) from the commercial truck 102B.

[0087] In commercial truck applications, due to the increased weight and therefore the longer stopping distance required for such vehicles, it is very important to effectively detect objects at all ranges. Due to the above advantages, FM LIDAR sensor systems (e.g., FMCW and / or FMQW systems) or PM LIDAR sensor systems are very suitable for commercial truck applications. Therefore, commercial trucks equipped with such systems can enhance the ability to transport people and goods over short or long distances. In various embodiments, such FM or PM LIDAR sensor systems can be used for semi-autonomous driving applications (wherein the commercial truck has a driver and certain functions of the commercial truck are automatically operated using the FM or PM LIDAR sensor system), or fully autonomous driving applications (wherein the commercial truck is completely operated 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 speed, and output these parameters to a remote system. For example, the LIDAR sensor system 500 can output the parameters for use by a vehicle controller (e.g., vehicle controller 598) that can control the operation of the vehicle in response to the received parameters, or 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 reference Figure 1-4 Various features and components of the system described herein. The LIDAR sensor system 500 may include components for performing various detection means, such as operating as an amplitude modular LIDAR system or a coherent LIDAR system. The LIDAR sensor system 500 may 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 located in the same housing, disposed in the same circuit board or other electronic assembly, 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 an optical signal (such as a light beam), or using a wired or wireless electronic connection for generating and / or receiving an electrical (e.g., data) signal.

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

[0091] The modulator 514 can modulate one or more properties of the input light beam 510 to generate a light beam 516 (e.g., a target light beam). In some embodiments, the modulator 514 can modulate the frequency of the input light beam 510 (e.g., an optical frequency corresponding to a wavelength of light, where c = λν, where c is the speed of light, λ is the wavelength, and ν is the frequency). For example, the modulator 514 can linearly modulate the frequency of the input light beam 510 so that the frequency of the light beam 516 increases or decreases linearly over time. As another example, the modulator 514 can modulate the frequency of the input light beam 510 nonlinearly (e.g., exponentially). In some embodiments, the modulator 514 can modulate the phase of the input light beam 510 to generate the light beam 516. However, the 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 light beam. Return 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 the modulated beam to beam splitter 508 so that beam splitter 508 splits it into a target beam and a reference beam.

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

[0093] The LIDAR sensor system 500 may include an optical module 524 that may receive the light beam 522. The optical module 524 may be a free-space optical device. For example, the optical module 524 may include one or more optical devices (e.g., lenses, mirrors, waveguides, grating couplers, prisms, wave plates) arranged with gaps (e.g., air gaps) between the one or more optical devices to allow free-space transmission of light (e.g., instead of all light being coupled between the optical devices 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 optical device 532 (e.g., a scanning optical 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 Figure 5 Circulator 608 can receive collimated light beam 612 output by collimator 604 and convert light beam 616 (e.g., Figure 5 500) is output to an optical device 532. In some embodiments, a circulator 608 can be located between the laser source 504 and the collimator 604. At least one of the collimator 604 or the circulator 608 can be a free-space optical device (and can be coupled to each other in free space), such as by optically coupling through an air gap rather than an optical fiber.

[0095] Further references Figure 5, the optical module 524 can receive the return beam 548 from the optical device 532 and provide the return beam 548 to the mixer 560. The optical device 532 can be: a scanning optical device, such as one or more turning 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., the cut surface) of the optical device 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] The optical device 532 can define a field of view 544 corresponding to an angle scanned (e.g., swept) by the light beam 542 (e.g., a transmitted light beam). For example, the light beam 542 can be scanned in a particular plane, such as an azimuth plane or an elevation plane (e.g., relative to an object to which the LIDAR sensor system 500 is coupled, such as an autonomous vehicle). The optical device 532 can be oriented so that the field of view 544 sweeps the azimuth plane relative to the optical device 532.

[0097] At least one motor 540 can be coupled to the optical device 532 to control at least one of the position or orientation of the optical device 532 relative to the light beam 530. For example, when the optical device 532 includes a reflector or a deflector, the motor 540 can rotate the optical device 532 so that the surface of the optical device 532 that receives 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] Light beam 542 may be output from optics 532 and reflected or otherwise scattered by an object (not shown) as return light beam 548 (eg, return signal). Return light beam 548 may be received on a receive path (which may include circulator 528) and provided to mixer 560.

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

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

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

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

[0103] 3.1 LIDAR sensor system including grating coupler for multi-directional reception

[0104] Figure 7 A block diagram of an example of a LIDAR sensor system 700 is depicted. The LIDAR sensor system 700 may be combined with the respective references Figure 5 and 6 Features of the LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 700 can facilitate pitch-catch compensation, i.e., accounting for time delays or other offsets caused by the round-trip path of a transmitted light beam, which is output from the LIDAR sensor system 700, reflected by an object or otherwise scattered, and then returned to the LIDAR sensor system 700 as a return light beam for detection and processing, which may 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 may be provided, including a transmitter 710 and a receiver 712. For example, the chip 705 may be a photonic integrated chip, such that the various components of the LIDAR sensor system 700 for generating, modulating, and processing optical signals and performing photonic operations are implemented by the chip 705. 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 material 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 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., Figure 5 and 6 The invention also provides a method for transmitting an emission beam 735 having a plurality of light beams (various light beams described) and outputting an emission light beam 735 having specific characteristics (such as direction, polarization, or various combinations thereof).

[0107] The 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 of the same or different sizes. The grating coupler 715 may be a structure formed by etching on the chip 705. The grating coupler 715 may be a structure formed by depositing a material on the 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 pattern, such as two-dimensional polarization. Thus, the grating coupler 715 can output an emission beam 735, such as based on a beam output by the laser source 504.

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

[0110] The LIDAR sensor system 700 may include at least one scanner 740, such as a steering mirror. Figure 5 , the scanner 740 can be coupled to the motor 540 so that the scanner 740 can be rotated in a direction relative to the emission beam 735 directed toward the scanner 740.

[0111] Scanner 740 can scan in both directions. For example, scanner 740 can scan in a first direction 760 and a second direction 765 (e.g., relative to a reference Figure 5 The scanner 740 can receive the transmission beam 735 from the transmitter 710 and direct the transmission beam 735 toward the environment surrounding the LIDAR sensor system 700. Figure 7 As shown, an object 702 may be present in the environment. The scanner 740 may receive a return beam 755 that is reflected or scattered from the object 702 to the transmission beam 735. In the time required for the transmission beam 735 to reach the object 702 and the return beam 755 to return from the object 702 to the scanner 740, the scanner 740 may have rotated a certain angle, as described more below. The scanner 740 may provide the return beam 755 to the receiver 712.

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

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

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

[0115] The grating couplers 725, 730 can receive a return beam 755 provided by the scanner 740. The grating couplers 725, 730 can couple light (e.g., the return beam 755) from free space onto the chip 705. As previously described, the scanner 740 can rotate during the time required for the transmitted beam 735 to travel to the object 702 and return to the receiver 712 as the return beam 755, which can cause the return beam 755 to be angularly displaced in the direction scanned by the scanner 740. When the return beam 755 is provided to the receiver 712, the angular displacement can appear as a translation in the focal plane. The translation can be referred to as focal plane drift. Since the grating couplers 725, 730 can couple light onto the chip 705 and are distinct from each other and spatially separated, grating couplers 725, 730 can be provided for two directions of focal plane drift. Furthermore, the translation distance may be optimized for a target time for transmit beam 735 to travel to object 702 and for return beam 755 to return from object 702 to receiver 712, and therefore for a specific range to object 702 (since the velocities of transmit beam 735 and return beam 755 are known).

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

[0117] The first polarization 780 may be different from the second polarization 785. The emission polarization 795 may be the same as the first polarization 780. For example, the grating coupler 715 may output the emission beam 735 at the first polarization 780. The grating couplers 725, 730 may receive the return beam 755 at the first polarization 780 or the second polarization 785. The second polarization 785 may be orthogonal to the first polarization 780.

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

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

[0120] Figure 8 7 is a block diagram of an example of optical components of system 800. System 800 may include components of various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement 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 transmit antenna 810, which may be implemented by a grating coupler 715 of a transmitter 710. For example, transmit antenna 810 may be an optical antenna integrated onto chip 705. Transmit antenna 810 may couple transmit beam 735 into free space. Transmit antenna 810 may be oriented at an angle corresponding to the polarization of transmit beam 735 relative to the surface on which transmit antenna 810 is located.

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

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

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

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

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

[0127] System 800 may include at least one mixer. The mixer may be similar or identical to 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, 845 may each be a 2x2 optical mixer. Mixers 840, 845 may each be an optical mixer. For example, mixers 840, 845 may each be a 90 degree optical mixer. For example, mixers 840, 845 may each be a 2x4 optical mixer.

[0128] The mixers 840, 845 can receive signals. For example, the mixer 840 can receive the reference beam 820, for example, the first LO signal. For example, the mixer 840 can receive the first component 770 of the return beam 755 from the receive antenna 825. For example, the mixer 845 can receive the reference beam 830, for example, the second LO signal. For example, the mixer 845 can receive the second component 775 of the return beam 755 from the receive antenna 835.

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

[0130] Fig. 9 Yes Figure 8 FIG. 9 is a block diagram of an example of a LIDAR sensor system 900 of an optical component. The LIDAR sensor system 900 may be combined with reference to Figure 5 and 6 Features of the LIDAR sensor system 500 and optical module 524 described above. The LIDAR sensor system 900 can facilitate pitch-catch compensation, including accounting for time delays or other offsets caused by the round-trip path of a transmitted light beam that is output from the LIDAR sensor system 700, reflected by an object or otherwise scattered, and then returned as a return light beam to the LIDAR sensor system 900 for detection and processing, which may otherwise affect 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 emission beam 735. The LIDAR sensor system 900 may include a scanner 740 configured to receive the emission beam 735 from the emitter 710, provide the emission beam 735 to the environment, and receive a return beam 755 that reflects the emission beam 735 from the 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 return beam 755 with a first polarization 780. The grating coupler 730 may receive a second component 775 of the return 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, the grating coupler 715 can output the emission beam 735 with an emission polarization 795, and the grating couplers 725, 730 can receive the components 770, 775 of the return beam 755 with polarizations 780, 785, each of which is orthogonal to the emission polarization 795.

[0133] The LIDAR sensor system 900 may include a shifter 905. The transmit beam 735 may 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 transmit beam 735, by a fixed amount. For example, the shifter 905 may shift the return beam 755 to the right of the transmit antenna 810 when received (e.g., relative to the orientation of the array during operation). The receive antennas 825, 835 are aligned with the polarizations 780, 785 of the components 770, 775 of the return beam 755. The receive antennas 825, 835 are located on both sides of the shifted return beam 755 so that they compensate for the above-mentioned focal plane drift at a specific target distance (e.g., the range of the object 702 to the scanner 740).

[0134] The LIDAR sensor system 900 can include the optical module 524 (e.g., the collimator 604 of the optical module 524). The collimator 604 can be located between the emitter 710 and the scanner 740. The emission beam 735 can pass through the collimator 604 without being affected. For example, the collimator 604 can be configured to provide the emission beam 735 to the scanner 740. The collimator 604 can be configured to collimate the emission beam 735. The collimator 604 can be configured to provide the collimated beam 910 to other components of the LIDAR sensor system 900, as described more below. For example, the collimator 604 can be configured to provide the collimated beam 910 to the scanner 740.

[0135] The LIDAR sensor system 900 can include a wave plate 915. The wave plate 915 can be a quarter wave plate. The emission beam 735 can pass through the wave plate 915 without being affected. The wave plate 915 can induce circular polarization. For example, the wave plate 915 can cause the components 770, 775 of the return beam 755 to be circularly polarized.

[0136] Fig.10 710 and 712. 712 is a block diagram of an example of optical components of system 1000. System 1000 may include components of various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement 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 polarization of the receive antennas 825, 835 is aligned with the polarization of the transmit antenna 810. As described above, the transmit antenna 810 may have the same polarization as the transmit polarization 795, the receive antenna 825 may have the same polarization as the first polarization 780, and the receive antenna 835 may have the same polarization as the second polarization 785. In system 1000, the transmit polarization 795 may be the same as the polarizations 780, 785, so that the transmit antenna 810 may have the same polarization as the receive antennas 825, 835.

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

[0139] Fig.11 Yes Fig.10FIG. 1 is a block diagram of an example of a LIDAR sensor system 1100 of an optical component. The LIDAR sensor system 1100 may be combined with reference to Figure 5 and 6 Features of the LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 1100 can facilitate pitch-catch compensation, i.e., accounting for time delays or other offsets caused by the round-trip path of a transmitted light beam, which is output from the LIDAR sensor system 1100, reflected by an object or otherwise scattered, and then returned to the LIDAR sensor system 1100 as a return light beam for detection and processing, which may 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 receive antennas 825, 835 is aligned with the polarization of transmit antenna 810, Fig.11 The block diagram depicted in Fig. 9 . However, since the polarization of the receiving antennas 825, 835 is 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 in the opposite polarization to the transmit beam 735, by a fixed amount. However, in the LIDAR sensor system 1100, when the polarizations 780, 785, 795 are the same, the shift of the return beam 755 is not required.

[0141] Fig.12 710 and receiver 712. The system 1200 may include components of the various LIDAR sensor systems described herein (such as the transmitter 710 and the receiver 712) and / or be used to implement the various LIDAR sensor systems described herein. For example, the 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, instead of communicating with a single photodetector (e.g., receiver 712) having two photodiodes (e.g., grating couplers 725, 730), mixers 840, 845 communicate with two independent and balanced photodetectors. Thus, system 1200 can include receiver 1205, e.g., a second receiver. Receiver 1205 can include grating coupler 730. Receiver 712 can include grating coupler 725. Mixer 840 can provide signal 850 to receiver 712, similar to system 800. However, in system 1200, mixer 845 can provide signal 855 to receiver 1205.

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

[0144] Fig.13 710 and 712. 713 is a block diagram of an example of optical components of system 1300. System 1300 may include components of various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement 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, rather than a single photodetector (e.g., receiver 712) having two photodiodes (e.g., grating couplers 725, 730). Thus, system 1300 can include receiver 1205. Receiver 1205 can include grating coupler 730. Receiver 712 can include grating coupler 725. Similar to system 800, mixer 840 can provide signal 850 to receiver 712. However, in system 1300, mixer 845 can provide signal 855 to receiver 1205. In addition, similar to system 1200, local oscillator 815 can be passively split between mixer 840 and mixer 845.

[0146] Fig.14 710 and 712. 712 is a block diagram of an example of optical components of system 1400. System 1400 may include components of various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement 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. Thus, 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 identical to 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 identical to reference beam 512. For example, local oscillator 1405 may transmit a third LO signal, e.g., reference beam 1410. For example, local oscillator 1405 may transmit a fourth LO signal, e.g., reference beam 1420. By switching the LO signal by local oscillator 1405, the amount of power required by local oscillator 1405 may be reduced.

[0148] System 1400 can include receive antenna 1415 and receive antenna 1425. Receive antennas 1415, 1425 are similar to receive antennas 825, 835. For example, receive antennas 1415, 1425 can receive return beam 755, as described below.

[0149] System 1400 can include mixer 1430 and mixer 1435. Mixers 1430, 1435 can be similar or identical to mixers 840, 845. Mixers 1430, 1435 can receive a signal, as described more below. Mixer 1430 can output signal 1440, as described more below. Mixer 1435 can output signal 1445, as described more below.

[0150] Fig.15 Yes Fig.14 FIG. 1 is a block diagram of an example of a LIDAR sensor system 1500 of an optical component. The LIDAR sensor system 1500 may be combined with reference to Figure 5 and 6 Features of the LIDAR sensor system 500 and optical module 524 are described. The LIDAR sensor system 1500 can facilitate pitch-catch compensation, i.e., accounting for time delays or other offsets caused by the round-trip path of a transmitted light beam, which is output from the LIDAR sensor system 1500, reflected by an object or otherwise scattered, and then returned to the LIDAR sensor system 1500 as a return light beam for detection and processing, which may 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 displacer 905 and a collimator 604, similar to Figure 8 . However, in system 1400, LIDAR sensor system 1500 may include wave plate 915. Wave plate 915 may be a quarter wave plate. Transmitted beam 735 may pass through wave plate 915 unaffected. Wave plate 915 may induce circular polarization. For example, wave plate 915 may circularly polarize a component of return beam 755.

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

[0153] As described above, the LIDAR sensor system 1500 may include a receiving antenna 1415 and a receiving antenna 1425 of the receiver 1205. The receiving antenna 1415 may be implemented by a 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 return beam 755 from free space onto the chip 705. The receiving antenna 1415 may be oriented at an angle corresponding to a third polarization 1515 of the third component 1505 of the return beam 755 relative to a surface on which the receiving antenna 1415 is disposed. The receiving antenna 1425 may be implemented by a 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 return beam 755 from free space onto the chip 705. The receive antenna 1425 can be oriented at an angle corresponding to a fourth polarization 1530 of the fourth component 1525 of the return light beam 755 relative to the surface on which the receive antenna 1425 is located.

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

[0155] Receive antenna 1425 can receive return beam 755. For example, receive antenna 1425 can receive fourth component 1525 of return beam 755. Thus, receive antenna 1425 can be oriented at the same polarization as fourth component 1525 of return beam 755. For example, receive antenna 1425 can have the same polarization as fourth polarization 1530. Receive antenna 1425 can provide fourth component 1525 of return beam 755 to mixer 1435.

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

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

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

[0159] Fig.16710 and 712. 712 is a block diagram of an example of optical components of system 1600. System 1600 may include components of various LIDAR sensor systems described herein (such as transmitter 710 and receiver 712) and / or be used to implement 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, 1435 communicate with two independent and balanced photodetectors instead of a single photodetector (e.g., receiver 1205). Thus, 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. In addition, 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 may use various optical components to generate light, encode information on the light, and output light to be reflected or otherwise scattered by objects in the environment surrounding the LIDAR sensor system 500. This may include, for example, at least some transmission of light through free space between components of the LIDAR sensor system 500, including in embodiments where light is provided by a laser source and modulated in frequency and / or phase using on-chip components, and then directed from the chip to scanning optics through collimation and / or circulator optics to be directed into the environment. Systems and methods according to the present disclosure may implement various such components to perform free space light transmission, maintain or improve signal-to-noise ratio, and reduce the overall size of the circulator.

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

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

[0165] Circulator 1700 may include an optical device 532, such as one or more scanning optical devices. Optical device 532 may have a scanning axis (e.g., reference Figure 5 The optical device 532 can rotate along the scanning axis 534. The grating coupler 725 and the grating coupler 730 can rotate along the scanning axis.

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

[0167] Circulator 1700 includes a shifter 905. Shifter 905 may be located between wave plate 1730 and optical device 532. Shifter 905 may be made of various materials, such as but not limited to A birefringent material is optically configured to control the path of light passing through the displacer 905 based on the polarization of the light. The thickness of the displacer 905 can be selected based on the target displacement amount and the type of material used for the displacer 905.

[0168] For example, the shifter 905 may be composed of The thickness of the displacer 905 can be between about 0.5 mm and 0.7 mm. For example, the thickness of the displacer 905 can be 0.6 mm. The displacer 905 can displace the return beam 755. For example, when the return beam 755 provided by the object 702 contacts the displacer 905, one of the two different refractive indices of the displacer 905 can displace a portion of the return beam 755, for example, the second component 775.

[0169] The displacer 905 can displace the second component 775 of the return beam 755. For example, the displacer 905 can displace the second component 775 of the return beam 755 so that the second component 775 is between about 32 microns and about 36 microns from the rotated emission beam 1715. For example, the displacer 905 can displace the second component 775 of the return beam 755 so that the second component 775 is 34 microns from the rotated emission beam 1715. For example, the displacer 905 can displace the second component 775 of the return beam 755 between about 18 microns and about 22 microns. For example, the displacer 905 can displace the second component 775 of the return beam 755 by 20 microns. For example, the displacer 905 can displace the second component 775 of the return beam 755 by 20 microns so that the second component 775 is 20 microns from the first component 770 of the return beam 755. Thus, since the second component 775 of the return beam 755 is displaced by approximately 18 and 22 microns, the spacing 1725 between the grating coupler 730 and the emitter 710 can be such that the grating coupler 730 can be positioned to receive the second component 775 of the return beam 755. For example, the spacing 1725 between the grating coupler 730 and the emitter 710 corresponds to the time delay and displacement of the second component 775 relative to the first component 770 by the circulator 1700.

[0170] The circulator 1700 can include a wave plate 1735. The wave plate 1735 can be located between the shifter 905 and the optics 532. The wave plate 1735 can be used to account for changes in polarization of the rotated transmit beam 1715 relative to a target polarization.

[0171] The circulator 1700 can direct the emission beam 735 to the optics 532. For example, the circulator 1700 can direct the emission 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 in 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 chip 705, for example, the plane of the chip 706, can simplify installation. 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., bonded) to the chip 705.

[0172] The circulator 1700 may receive the emission beam 735 and provide the emission beam 735 to the optical device 532. For example, the emission beam 735 may pass through the wave plate 1730 and the shifter 905 and contact the optical device 532. The circulator 1700 may receive the return beam 755 of the reflection of the emission beam 735 by the object 702. For example, the return beam 755 may contact the shifter 905. The circulator 1700 may split the return beam 755 into at least a first component 770 and a second component 775. For example, the circulator 1700 may split the return beam 755 into at least a first component 770 and a second component 775 via the shifter 905, as described above. The circulator 1700 may 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 may pass through the wave plate 1730 to reach the grating coupler 725 and the grating coupler 730, respectively.

[0173] Circulator 1700 can rotate emission beam 735 and provide the rotated emission beam 1715 to optics 532. For example, emission beam 735 can contact wave plate 1730 and wave plate 1730 can rotate emission beam 735. Wave plate 1730 can provide the rotated emission beam 1715 to displacer 905. The rotated emission beam 1715 can pass through displacer 905 unaffected and contact optics 532.

[0174] The circulator 1700 can polarize the first component 770 of the return beam 755. For example, the return beam 755 can be returned from the object 702 unpolarized. The return beam 755 can contact the shifter 905. The shifter 905 can rotate (e.g., polarize) the first component 770 of the return beam 755 so that the polarization associated with the first component 770 corresponds to the polarization of the rotated emission beam 1715. The first component 770 of the return beam 755 can contact the wave plate 1730. The wave plate 1730 can rotate (e.g., polarize) the first component 770 of the return beam 755 to provide the first component 770 in a first polarization 780. The wave plate 1730 can rotate (e.g., polarize) the first component 770 of the return beam 755 so that the first polarization 780 associated with the first component 770 corresponds to the emission polarization 795 associated with the emission beam 735. For example, the wave plate 1730 can rotate the first component 770 of the return beam 755 by 45 degrees.

[0175] The circulator 1700 can polarize the second component 775 of the return beam 755. For example, the return beam 755 can be returned from the object 702 unpolarized. The return beam 755 can contact the shifter 905. The shifter 905 can shift the second component 775 of the return beam 755, as described above. The shifter 905 can rotate (e.g., polarize) the second component 775 of the return beam 755 so that the polarization associated with the second component 775 is orthogonal to the polarization of the rotated emission beam 1715. The second component 775 of the return beam 755 can contact the wave plate 1730. The wave plate 1730 can rotate (e.g., polarize) the second component 775 of the return beam 755 to provide the second component 775 in a second polarization 785. The wave plate 1730 can rotate (e.g., polarize) the second component 775 of the return beam 755 so that the second polarization 785 associated with the second component 775 is orthogonal to the emission polarization 795 associated with the emission beam 735. For example, the wave plate 1730 can rotate the second component 775 of the return 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 contact the wave plate 1730, the wave plate 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 the 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 the components 770, 775. The grating coupler 725 can receive at least a first threshold amount (e.g., greater than about thirty percent; between about thirty percent and about ninety percent; between about fifty percent and about eighty percent) of the first component 770 of the return beam 755. For example, the first threshold amount can correspond to an amount required for the grating coupler 725 to output a signal (e.g., signal 850). The grating coupler 730 can receive at least a second threshold amount (e.g., greater than about thirty percent; between about thirty percent and about ninety percent; between about fifty percent and about eighty percent) of the second component 775 of the return beam 755. For example, the second threshold amount can correspond to an amount required for the grating coupler 730 to output a signal (e.g., signal 855).

[0177] Now that some illustrative embodiments have been described, it is apparent that the foregoing is illustrative and not restrictive, and has been presented by way of example. Specifically, although many of the examples presented herein involve specific combinations of method behaviors or system elements, these behaviors and these elements may be combined in other ways to achieve the same goals. Behaviors, elements, and features discussed in relation to one embodiment are not intended to be excluded from similar roles in other embodiments.

[0178] The words and terms used herein are for descriptive purposes and should not be considered limiting. The use of "including," "comprising," "having," "containing," "involving," "characterized by," "characterized by," and variations thereof herein is intended to encompass the items listed subsequently, their equivalents and additional items, and alternative embodiments consisting solely of the items listed subsequently. In one embodiment, the systems and methods described herein consist of one of the described elements, behaviors, or components, a combination of a plurality of the described elements, behaviors, or components, or all of the described elements, behaviors, or components.

[0179] Any reference to an embodiment or element or behavior of a system and method mentioned herein in the singular may also encompass an embodiment including a plurality of such elements, and any reference to any embodiment or element or behavior herein in the plural may also encompass an embodiment including only a single element. Reference in the singular or plural form is not intended to limit the currently disclosed system or method, its components, behaviors, or elements to a single or plural configuration. Reference to any behavior or element based on any information, behavior, or element may include an embodiment in which the behavior or element is based at least in part on any information, behavior, or element.

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

[0181] When a technical feature in the drawings, detailed description or any claims is followed by a reference numeral, the reference numeral has been included to increase the intelligibility of the drawings, detailed description and claims. Therefore, neither the reference numeral nor its absence will 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 relative parallel, perpendicular, vertical or other positioning or orientation descriptions include variations within + / -10% or + / -10 degrees of pure vertical, parallel or perpendicular positioning. Unless otherwise expressly stated, references to "approximately", "about", "substantially" or other degree terms include variations of + / -10% relative to a given measurement, unit or range. The coupled 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 the equivalent content of the claims are included therein.

[0183] The term "coupled" and its variations include two members being connected directly or indirectly to one another. Such connection may be fixed (e.g., permanent or fixed) or removable (e.g., removable or releasable). Such connection may be achieved by the two members being directly coupled or coupled to one another; the two members being coupled to one another using a separate intermediate member and any other intermediate members that are coupled to one another; or the two members being coupled to one another using an intermediate member that is integrally formed as a single unitary body with one of the two members. If "coupled" or its variations are modified by additional terms (e.g., directly coupled), the general definition of "coupled" provided above will be modified by the ordinary language meaning of the additional terms (e.g., "directly coupled" means the connection of two members without any separate intermediate members), resulting in a narrower definition than the general definition of "coupled" provided above. Such coupling may be mechanical, electrical, or fluid.

[0184] References to "or" may be interpreted as inclusive, so any term described using "or" may mean any of the singular, plural, and all of the terms. References to "at least one of 'A' and 'B'" may include only 'A', only 'B', and both 'A' and 'B'. Such references used in conjunction with "including" or other open terminology may include additional items.

[0185] Modifications may be made to the elements and behaviors, such as changes in size, dimensions, structure, shape and proportions, parameter values, mounting arrangements, material usage, color, orientation of various elements, without materially departing from the teachings and advantages of the subject matter disclosed herein. For example, an element shown as being integrally formed may be composed of multiple parts or elements, the position of an element may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions, and arrangement of the disclosed elements and operations without departing from the scope of the present disclosure.

[0186] References to element positions herein (e.g., "top," "bottom," "above," "below") are only used 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 encompassed by the present disclosure.

Claims

1. A light detection and ranging (LIDAR) sensor system for a vehicle, comprising: an emitter configured to output an emission light beam; Receiver, comprising: a first receiving grating coupler; and a second receiving grating coupler; one or more scanning optics; and A circulator, the circulator being configured to: receiving the emission light beam and providing the emission light beam to the one or more scanning optics; receiving a return light beam reflected by an object from the emitted light beam; splitting the return beam into at least a first component and a second component; and The first component is provided to the first receive grating coupler and the second component is provided to the second receive grating coupler.

2. The LIDAR sensor system according to claim 1, wherein: The emission light beam has polarization, and the circulator is further configured to: rotating the polarization of the emission beam and providing the rotated emission beam to the one or more scanning optics; polarizing the first component of the return beam so that the polarization of the first component corresponds to the polarization of the transmitted beam; polarizing the second component of the return beam such that the polarization of the second component is orthogonal to the polarization of the transmitted beam; and The respective polarizations of the first component and the second component of the return beam are rotated by 45 degrees to provide the rotated first component to the first receive grating coupler and the rotated second component to the second receive grating coupler.

3. The LIDAR sensor system according to claim 1, wherein: The circulator comprises: a half-wave plate positioned between the emitter and the one or more scanning optics; and A shifter is positioned between the half wave plate and the one or more scanning optics.

4. The LIDAR sensor system of claim 1, wherein: The circulator comprises: a first half-wave plate positioned between the emitter and the one or more scanning optics; a shifter positioned between the half-wave plate and the one or more scanning optics; and A second half wave plate is positioned between the shifter and the one or more scanning optics.

5. The LIDAR sensor system of claim 1, wherein: The first receiving grating coupler is spaced from the emitter by a distance between about 8 microns and about 20 microns; and The second receiving grating coupler is spaced apart from the emitter by a distance between about 30 microns and about 50 microns.

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

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

8. The LIDAR sensor system of claim 1, wherein: The first receive grating coupler receives at least about fifty percent of the first component of the return light beam; and The second receive grating coupler receives at least about fifty percent of the second component of the return light beam.

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

10. The LIDAR sensor system of claim 1, wherein: The circulator comprises: Depend on A displacer is formed and has a thickness between about 0.53 mm and about 0.65 mm, the displacer is located between the emitter and the one or more scanning optical devices, and is configured to displace the second component of the return beam between about 18 and about 22 microns.

11. The LIDAR sensor system of claim 1 , wherein: The emitter is located on a chip and is configured to output the emission light beam at an angle to the plane of the chip.

12. The LIDAR sensor system of claim 11, wherein: The circulator is configured to direct the emission light beam in a direction parallel to the plane to the one or more scanning optics.

13. An autonomous driving vehicle control system, comprising: an emitter configured to output an emission light beam; a receiver, the receiver comprising a first receiving grating coupler and a second receiving grating coupler; Scanner; A circulator, the circulator being configured to: receiving the emitted light beam and directing the emitted light beam to the scanner; receiving a return light beam reflected by an object from the emitted light beam; splitting the return beam into at least a first component and a second component; as well as directing the first component to the first receive grating coupler and directing the second component to the second receive grating coupler; as well as One or more processors configured to: determining at least one of a distance to the object or a velocity of the object based on the first component and the second component; as well as 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 the light beam output by the transmitter as the transmitted light beam.

15. The autonomous driving vehicle control system according to claim 13, wherein: The emission light beam has polarization, and the circulator is further configured to: rotating the polarization of the emission beam and providing the rotated emission beam to the scanner; polarizing the first component of the return beam so that the polarization of the first component corresponds to the polarization of the transmitted beam; polarizing the second component of the return beam such that the polarization of the second component is orthogonal to the polarization of the transmitted beam; as well as The respective polarizations of the first component and the second component of the return beam are rotated by 45 degrees to provide the rotated first component to the first receive grating coupler and the rotated second component to the second receive grating coupler.

16. The autonomous driving vehicle control system of claim 13, wherein: The first receiving grating coupler is spaced a first distance from the transmitter, the first distance corresponding to a time delay associated with a target distance for detecting the object; and The second receiving grating coupler is spaced apart from the transmitter by a second distance, and the second distance corresponds to the time delay and the displacement of the second component relative to the first component by the circulator.

17. The autonomous driving vehicle control system of claim 13, wherein: The first receive grating coupler receives at least about fifty percent of the first component of the return light beam; and The second receive grating coupler receives at least about fifty percent of the second component of the return light beam.

18. An autonomous driving vehicle comprising: LIDAR sensor system, including: an emission grating coupler configured to output an emission light beam; a first receiving grating coupler; a second receiving grating coupler; Scanners; and A circulator, the circulator being configured to: receiving the emission light beam and providing the emission light beam to the scanner; receiving a return light beam reflected by an object from the emitted light beam; splitting the return beam into at least a first component and a second component; and directing the first component to the first receive grating coupler and directing the second component to the second receive grating coupler; Steering system; Braking system; and A vehicle controller comprising one or more processors configured to: determining at least one of a distance to the object or a velocity of the object using the first component and the second component; and Operation of at least one of the steering system and the braking system is controlled in response to the at least one of the distance or the speed.

19. The autonomous driving vehicle of claim 18, wherein: The emission light beam has polarization, and the circulator is further configured to: rotating the polarization of the emission beam and providing the rotated emission beam to the scanner; polarizing the first component of the return beam so that the polarization of the first component corresponds to the polarization of the transmitted beam; polarizing the second component of the return beam such that the polarization of the second component is orthogonal to the polarization of the transmitted beam; as well as The respective polarizations of the first component and the second component of the return beam are rotated by 45 degrees to provide the rotated first component to the first receive grating coupler and the rotated second component to the second receive grating coupler.

20. The autonomous driving vehicle of claim 18, wherein: The first receive grating coupler receives at least about fifty percent of the first component of the return light beam; and The second receive grating coupler receives at least about fifty percent of the second component of the return light beam.

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