Metalens for lidar light receiver

Abstract

A LiDAR light receiver is provided. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

Description

Attorney Docket Number: 11325.10209W001METALENS FOR LIDAR LIGHT RECEIVER CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No.63 / 721,970, filed November 18, 2024, entitled “METALENS OPTIMIZATION FOR LIDAR”, the content of which is hereby incorporated by reference in its entirety for all purposes.FIELD OF THE TECHNOLOGY

[0002] This disclosure relates generally to optical scanning and, more particularly, to configuring a Metalens or a Metalens group for LiDAR receivers.BACKGROUND

[0003] Light detection and ranging (LiDAR) systems use light pulses to create an image or point cloud of the external environment. A LiDAR system may be a scanning or non-scanning system. Some typical scanning LiDAR systems include a light source, a light transmitter, a light steering system, and a light detector. The light source generates a light beam that is directed by the light steering system in particular directions when being transmitted from the LiDAR system. When a transmitted light beam is scattered or reflected by an object, a portion of the scattered or reflected light returns to the LiDAR system to form a return light pulse. The light detector detects the return light pulse. Using the difference between the time that the return light pulse is detected and the time that a corresponding light pulse in the light beam is transmitted, the LiDAR system can determine the distance to the object based on the speed of light. This technique of determining the distance is referred to as the time-of-flight (ToF) technique. The light steering system can direct light beams along different paths to allow the LiDAR system to scan the surrounding environment and produce images or point clouds. A typical non-scanning LiDAR system illuminates an entire field-of-view (FOV) rather than scanning through the FOV. An example of the non-scanning LiDAR system is a flash LiDAR, which can also use the ToF technique to measure the distance to an object. LiDAR systems can also use techniques other than time-of-flight and scanning to measure the surrounding environment.Attorney Docket Number: 11325.10209W001SUMMARY

[0004] In one embodiment of the present disclosure, a LiDAR light receiver is provided. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

[0005] In one embodiment of the present disclosure, a LiDAR light receiver is provided. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The Metalens or Metalens group includes at least an inner region having a first focusing power, and an outer region having a second focusing power greater than the first focusing power. The lens or lens group is configured to receive return light. The return light includes at least a first group of return light from one or more far objects in a FOV, and a second group of return light from one or more near objects in the FOV. The one or more far objects are located further from the LiDAR light receiver than the one or more near objects. The lens or lens group is further configured to focus and direct the return light toward the Metalens or Metalens group, such that the first group of return light passes though the inner region of the Metalens or Metalens group, and the second group of return light passes though the outer region of the Metalens or Metalens group. The Metalens or the Metalens group is configured to focus the first group of return light with the first focusing power, and focus the second group of return light with second focusing power, such that both the first group of return light and the second groups of return light substantially converge to their respective focal points on the detector array. The detector array is configured to detect the focused first group of return light and the focused second group of the return light.

[0006] In one embodiment of the present disclosure, a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array.Attorney Docket Number: 11325.10209W001The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

[0007] In one embodiment of the present disclosure, a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The Metalens or Metalens group includes at least an inner region having a first focusing power, and an outer region having a second focusing power greater than the first focusing power. The lens or lens group is configured to receive return light. The return light includes at least a first group of return light from one or more far objects in a FOV, and a second group of return light from one or more near objects in the FOV. The one or more far objects are located further from the LiDAR light receiver than the one or more near objects. The lens or lens group is further configured to focus and direct the return light toward the Metalens or Metalens group, such that the first group of return light passes though the inner region of the Metalens or Metalens group, and the second group of return light passes though the outer region of the Metalens or Metalens group. The Metalens or the Metalens group is configured to focus the first group of return light with the first focusing power, and focus the second group of return light with second focusing power, such that both the first group of return light and the second groups of return light substantially converge to their respective focal points on the detector array. The detector array is configured to detect the focused first group of return light and the focused second group of the return light.

[0008] In one embodiment of the present disclosure, a vehicle including a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return lightAttorney Docket Number: 11325.10209W001overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

[0009] In one embodiment of the present disclosure, a vehicle including a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The Metalens or Metalens group includes at least an inner region having a first focusing power, and an outer region having a second focusing power greater than the first focusing power. The lens or lens group is configured to receive return light. The return light includes at least a first group of return light from one or more far objects in a FOV, and a second group of return light from one or more near objects in the FOV. The one or more far objects are located further from the LiDAR light receiver than the one or more near objects. The lens or lens group is further configured to focus and direct the return light toward the Metalens or Metalens group, such that the first group of return light passes though the inner region of the Metalens or Metalens group, and the second group of return light passes though the outer region of the Metalens or Metalens group. The Metalens or the Metalens group is configured to focus the first group of return light with the first focusing power, and focus the second group of return light with second focusing power, such that both the first group of return light and the second groups of return light substantially converge to their respective focal points on the detector array. The detector array is configured to detect the focused first group of return light and the focused second group of the return light.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present application can be best understood by reference to the embodiments described below taken in conjunction with the accompanying drawing figures, in which like parts may be referred to by like numerals.

[0011] FIG. 1 illustrates one or more example LiDAR systems disposed or included in a motor vehicle.Attorney Docket Number: 11325.10209W001

[0012] FIG. 2A is a block diagram illustrating interactions between an example LiDAR system and multiple other systems including a vehicle perception and planning system.

[0013] FIG. 2B is a block diagram illustrating interactions between robot central system and multiple other systems including sensors, actuators, a user interface and a facility network.

[0014] FIG. 3 is a block diagram illustrating an example LiDAR system.

[0015] FIG. 4A is a block diagram illustrating an example fiber-based laser source.

[0016] FIG. 4B is a block diagram illustrating an example semiconductor-based laser source.

[0017] FIGs. 5A-5C illustrate an example LiDAR system using pulse signals to measure distances to objects disposed in a field-of-view (FOV).

[0018] FIG. 6 is a block diagram illustrating an example apparatus used to implement systems, apparatus, and methods in various embodiments.

[0019] FIG. 7 is a diagram illustrating an example of a typical LiDAR light receiver designed with typical optical lenses or lens groups.

[0020] FIG. 8 is a diagram illustrating an example of Metalenses formed on a wafer in accordance with various embodiments.

[0021] FIGs. 9A-9D are diagrams illustrating examples of LiDAR light receivers having a Metalens or Metalens group in accordance with various embodiments.

[0022] FIGs. 10A and 10B are diagrams illustrating an example of using a multi -focus Metalens or Metalens group to improve LiDAR system performance in accordance with various embodiments.DETAILED DESCRIPTION

[0023] To provide a more thorough understanding of various embodiments of the present invention, the following description sets forth numerous specific details, such as specific configurations, parameters, examples, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present invention but is intended to provide a better description of the exemplary embodiments.Attorney Docket Number: 11325.10209W001

[0024] Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise:

[0025] The phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment, though it may. Thus, as described below, various embodiments of the disclosure may be readily combined, without departing from the scope or spirit of the invention.

[0026] As used herein, the term “or” is an inclusive “or” operator and is equivalent to the term “and / or,” unless the context clearly dictates otherwise.

[0027] The term “based on” is not exclusive and allows for being based on additional factors not described unless the context clearly dictates otherwise.

[0028] As used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously. Within the context of a networked environment where two or more components or devices are able to exchange data, the terms “coupled to” and “coupled with” are also used to mean “communicatively coupled with”, possibly via one or more intermediary devices. The components or devices can be optical, mechanical, and / or electrical devices.

[0029] Although the following description uses terms “first,” “second,” etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another. For example, a first focusing power could be termed a second focusing power and, similarly, a second focusing power could be termed a first focusing power, without departing from the scope of the various described examples. The first focusing power and the second focusing power can both be focusing powers and, in some cases, can be separate and different focusing power.

[0030] In addition, throughout the specification, the meaning of “a”, “an”, and “the” includes plural references, and the meaning of “in” includes “in” and “on”.

[0031] Although some of the various embodiments presented herein constitute a single combination of inventive elements, it should be appreciated that the inventive subject matter is considered to include all possible combinations of the disclosed elements. As such, if oneAttorney Docket Number: 11325.10209W001embodiment comprises elements A, B, and C, and another embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly discussed herein. Further, the transitional term “comprising” means to have as parts or members, or to be those parts or members. As used herein, the transitional term “comprising” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.

[0032] As used in the description herein and throughout the claims that follow, when a system, engine, server, device, module, or other computing element is described as being configured to perform or execute functions on data in a memory, the meaning of “configured to” or “programmed to” is defined as one or more processors or cores of the computing element being programmed by a set of software instructions stored in the memory of the computing element to execute the set of functions on target data or data objects stored in the memory.

[0033] It should be noted that any language directed to a computer should be read to include any suitable combination of computing devices or network platforms, including servers, interfaces, systems, databases, agents, peers, engines, controllers, modules, or other types of computing devices operating individually or collectively. One should appreciate the computing devices comprise a processor configured to execute software instructions stored on a tangible, non-transitory computer readable storage medium (e.g., hard drive, FPGA, PLA, solid state drive, RAM, flash, ROM, or any other volatile or non-volatile storage devices). The software instructions configure or program the computing device to provide the roles, responsibilities, or other functionality as discussed below with respect to the disclosed apparatus. Further, the disclosed technologies can be embodied as a computer program product that includes a non-transitory computer readable medium storing the software instructions that causes a processor to execute the disclosed steps associated with implementations of computer-based algorithms, processes, methods, or other instructions. In some embodiments, the various servers, systems, databases, or interfaces exchange data using standardized protocols or algorithms, possibly based on HTTP, HTTPS, AES, public-private key exchanges, web service APIs, known financial transaction protocols, or other electronic information exchanging methods. Data exchanges among devices can be conducted over a packet-switched network, the Internet, LAN, WAN, VPN, or other type of packet switched network; a circuit switched network; cell switched network; or other type of network.Attorney Docket Number: 11325.10209W001

[0034] LiDAR is a three-dimensional (3D) sensing device that is increasingly being used in robotics, autonomous driving vehicles, and vehicles with high-level advanced driver assistance system (ADAS) features. A current LiDAR system often includes transmitter optics and receiver optics designed with typical optical lenses and lens groups. The optical lenses or lens groups may be formed by bulky glass-based components. For example, a transmitter of a LiDAR system may include a collimation lens group configured to collimate laser light to form collimated transmission light beams. To collimate a large number of laser light beams, the collimation lens group typically includes multiple optical lenses and / or prisms, arranged in a specific way to manipulate the large number of laser light beams and create parallel light rays for each of the laser light beams at its output. With so many optical elements, the collimation lens group inevitably occupies a large space, making the LiDAR system bulky. The multiple optical elements also increase the manufacturing costs, making the LiDAR system more expensive.

[0035] In another example, a LiDAR light receiver is often quite bulky if typical optical lenses or lens groups are used. When the transmission light beams are scattered or reflected by one or more objects, a portion of the scattered or reflected light forms return light that returns to the LiDAR system. The LiDAR light receiver is configured to collect and focus the return light onto a LiDAR detector. Due to the large number of the transmission light beams, the return light can also include many groups of return light corresponding to the large number of transmission light beams. In turn, the LiDAR detector also includes multiple light detectors arranged in a detector array (e.g., ID or 2D detector array), so that the many groups of return light can be detected in parallel. This enables the LiDAR system to generate better quality point cloud. In order to precisely focus the many groups of return light to the corresponding light detectors in the detector array, multiple optical lenses and / or filters are used. As a result, the multiple optical elements occupy a large space, further making the LiDAR system bulky.

[0036] Further, to collect more return light from a large FOV, a large front-end optical aperture is often required for the LiDAR light receiver. As a result, a large size optical lens is used at the front end of the LiDAR light receiver to collect as much return light as possible. The large frontend optical aperture also affects other lenses positioned downstream in the receiving optical path, further increasing the overall size of the LiDAR light receiver. The combination of multiple and large-size lenses further increases manufacturing costs and difficulties in LiDAR system assembly. For example, a large and complex lens housing with mechanical structures to hold theAttorney Docket Number: 11325.10209W001multiple optical elements align is also required, thereby making the LiDAR system even more bulky and expensive. Therefore, there is a need for techniques to optimize the LiDAR light receiver to use fewer, reduced size, and lower cost optical components.

[0037] Metalenses are optical components that use metasurfaces to direct light (e.g., focus light). A Metalens is sometimes also referred to as a metamaterial lens, which is an advanced type of lens that uses metamaterials to manipulate and control light in specific ways. Typical optical lenses, such as glass-based lenses, rely on the curvature of their surfaces to focus light.Metalenses, on the other hand, are thin and include subwavelength structures at the nanoscale, which can interact with light in ways that typical optical lenses can or cannot. Therefore, a Metalens can compensate for optical aberration and distortions that usually require multiple typical optical lenses. As a result, multiple optical lenses with different curvatures of their surfaces can be replaced by a thin piece of Metalens, thereby greatly reducing bulkiness of the traditional optics. Moreover, Metalenses are capable of being mass produced using well-developed wafer manufacturing processes. Therefore, Metalenses can also potentially compete with multiple typical lenses on production costs, enabling more compact and cost-effective LiDAR systems. Metalenses and their applications in LiDAR systems are described in more detail in U.S. non-provisional patent application No. 18 / 373,252, filed on September 26, 2023, entitled “COMPACT LIDAR SYSTEM WITH METALENSES”, the content of which is incorporated by reference in it is entirety for all purposes.

[0038] In this disclosure, by using Metalenses in combination with typical optics, an improved LiDAR light receiver is provided. The improved LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. By using the Metalens or Metalens group in the LiDAR light receiver, three or more typical optical lenses (e.g., glass-based lenses) can be replaced, thereby greatly reducing the bulkiness of the LiDAR system and lowering the manufacturing costs of the light receiver. Further, due to the thin-and-flat nature of the Metalens, the lens mounting and assembly also becomes easier, thereby further reducing the costs on mechanical housing. It is understood that Metalens may appear flat when viewed at the macroscopic level (e.g., with naked eyes) but may have nanostructures when viewed at the microscopic level (e.g., with a microscope).Attorney Docket Number: 11325.10209W001

[0039] In addition, a Metalens or Metalens group can be customized to be multi-focus, which is very difficult to achieve with typical glass-based optics fabrication. For example, a LiDAR light receiver can include a Metalens or Metalens group with different focusing powers at its inner region and outer region for focusing return light from far objects and near objects, respectively. As a result, return light from both far objects and near objects can be focused on detector arrays using the same Metalens or Metalens group, thereby improving detection performance and efficiency of the LiDAR system.

[0040] Embodiments of present invention are described below. In various embodiments of the present invention, a LiDAR light receiver is provided. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

[0041] In another example, a LiDAR light receiver is provided. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The Metalens or Metalens group includes at least an inner region having a first focusing power, and an outer region having a second focusing power greater than the first focusing power. The lens or lens group is configured to receive return light. The return light includes at least a first group of return light from one or more far objects in a FOV, and a second group of return light from one or more near objects in the FOV. The one or more far objects are located further from the LiDAR light receiver than the one or more near objects. The lens or lens group is further configured to focus and direct the return light toward the Metalens or Metalens group, such that the first group of return light passes though the inner region of the Metalens or Metalens group, and the second group of return light passes though the outer region of the Metalens or Metalens group. The Metalens or the Metalens group is configured to focus the first group of return light with the first focusing power, and focus the second group of return light with second focusing power, such that both the first group of return light and the second groups of return lightAttorney Docket Number: 11325.10209W001substantially converge to their respective focal points on the detector array. The detector array is configured to detect the focused first group of return light and the focused second group of the return light.

[0042] In another example, a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

[0043] In another example, a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The Metalens or Metalens group includes at least an inner region having a first focusing power, and an outer region having a second focusing power greater than the first focusing power. The lens or lens group is configured to receive return light. The return light includes at least a first group of return light from one or more far objects in a FOV, and a second group of return light from one or more near objects in the FOV. The one or more far objects are located further from the LiDAR light receiver than the one or more near objects. The lens or lens group is further configured to focus and direct the return light toward the Metalens or Metalens group, such that the first group of return light passes though the inner region of the Metalens or Metalens group, and the second group of return light passes though the outer region of the Metalens or Metalens group. The Metalens or the Metalens group is configured to focus the first group of return light with the first focusing power, and focus the second group of return light with second focusing power, such that both the first group of return light and the second groups of return light substantially converge to their respective focal points on the detector array. The detector array is configured to detect the focused first group of return light and the focused second group of the return light.Attorney Docket Number: 11325.10209W001

[0044] In another example, a vehicle including a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The lens or lens group is configured to receive multiple groups of return light from one or more objects in a FOV, and focus and direct the multiple groups of return light toward the Metalens or Metalens group, such that portions of the multiple groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region. The Metalens or the Metalens group is configured to focus and direct the multiple groups of return light to the detector array, such that the multiple groups of return light are received by the detector array within a convergence region.

[0045] In another example, a vehicle including a system for LiDAR is provided. The system includes a light source, a scanner, a controller, and a LiDAR light receiver. The LiDAR light receiver includes a lens or lens group, a Metalens or Metalens group, and a detector array. The Metalens or Metalens group includes at least an inner region having a first focusing power, and an outer region having a second focusing power greater than the first focusing power. The lens or lens group is configured to receive return light. The return light includes at least a first group of return light from one or more far objects in a FOV, and a second group of return light from one or more near objects in the FOV. The one or more far objects are located further from the LiDAR light receiver than the one or more near objects. The lens or lens group is further configured to focus and direct the return light toward the Metalens or Metalens group, such that the first group of return light passes though the inner region of the Metalens or Metalens group, and the second group of return light passes though the outer region of the Metalens or Metalens group. The Metalens or the Metalens group is configured to focus the first group of return light with the first focusing power, and focus the second group of return light with second focusing power, such that both the first group of return light and the second groups of return light substantially converge to their respective focal points on the detector array. The detector array is configured to detect the focused first group of return light and the focused second group of the return light.

[0046] FIG. 1 illustrates one or more example LiDAR systems 110 and 120A-120M disposed or included in a motor vehicle 100. Vehicle 100 can be a car, a sport utility vehicle (SUV), a truck, a train, a wagon, a bicycle, a motorcycle, a tricycle, a bus, a mobility scooter, a tram, a ship, aAttorney Docket Number: 11325.10209W001boat, an underwater vehicle, an airplane, a helicopter, an unmanned aviation vehicle (UAV), a spacecraft, etc. Motor vehicle 100 can be a vehicle having any automated level. For example, motor vehicle 100 can be a partially automated vehicle, a highly automated vehicle, a fully automated vehicle, or a driverless vehicle. A partially automated vehicle can perform some driving functions without a human driver’s intervention. For example, a partially automated vehicle can perform blind-spot monitoring, lane keeping and / or lane changing operations, automated emergency braking, smart cruising and / or traffic following, or the like. Certain operations of a partially automated vehicle may be limited to specific applications or driving scenarios (e.g., limited to only freeway driving). A highly automated vehicle can generally perform all operations of a partially automated vehicle but with less limitations. A highly automated vehicle can also detect its own limits in operating the vehicle and ask the driver to take over the control of the vehicle when necessary. A fully automated vehicle can perform all vehicle operations without a driver’s intervention but can also detect its own limits and ask the driver to take over when necessary. A driverless vehicle can operate on its own without any driver intervention.

[0047] In typical configurations, motor vehicle 100 comprises one or more LiDAR systems 110 and 120A-120M. Each of LiDAR systems 110 and 120A-120M can be a scanning-based LiDAR system and / or a non-scanning LiDAR system (e.g., a flash LiDAR). A scanning-based LiDAR system scans one or more light beams in one or more directions (e.g., horizontal and vertical directions) to detect objects in a field-of-view (FOV). A non-scanning based LiDAR system transmits laser light to illuminate an FOV without scanning. For example, a flash LiDAR is a type of non-scanning based LiDAR system. A flash LiDAR can transmit laser light to simultaneously illuminate an FOV using a single light pulse or light shot.

[0048] A LiDAR system is a frequently-used sensor of a vehicle that is at least partially automated. In one embodiment, as shown in FIG. 1, motor vehicle 100 may include a single LiDAR system 110 (e.g., without LiDAR systems 120A-120M) disposed at the highest position of the vehicle (e.g., at the vehicle roof). Disposing LiDAR system 110 at the vehicle roof facilitates a 360-degree scanning around vehicle 100. In some other embodiments, motor vehicle 100 can include multiple LiDAR systems, including two or more of systems 110 and / or 120A-120M. As shown in FIG. 1, in one embodiment, multiple LiDAR systems 110 and / or 120A-120M are attached to vehicle 100 at different locations of the vehicle. For example, LiDARAttorney Docket Number: 11325.10209W001system 120A is attached to vehicle 100 at the front right corner; LiDAR system 120B is attached to vehicle 100 at the front center position; LiDAR system 120C is attached to vehicle 100 at the front left corner; LiDAR system 120D is attached to vehicle 100 at the right-side rear view mirror; LiDAR system 120E is attached to vehicle 100 at the left-side rear view mirror; LiDAR system 120F is attached to vehicle 100 at the back center position; LiDAR system 120G is attached to vehicle 100 at the back right comer; LiDAR system 120H is attached to vehicle 100 at the back left comer; and / or LiDAR system 1201 is attached to vehicle 100 at the center towards the backend (e.g., back end of the vehicle roof); LiDAR system 120J is attached to the right A-pillar of vehicle 100; LiDAR system 120K is attached to the left A-pillar of vehicle 100; LiDAR system 120L is attached to the right B-pillar of vehicle 100; and LiDAR system 120M is attached to the left B-pillar of vehicle 100. It is understood that one or more LiDAR systems can be distributed and attached to a vehicle in any desired manner and FIG. 1 only illustrates one embodiment. As another example, LiDAR system 120B may be attached to the windshield of vehicle 100 instead of the front bumper.

[0049] In some embodiments, LiDAR systems 110 and 120A-120M are independent LiDAR systems having their own respective laser sources, control electronics, transmitters, receivers, and / or steering mechanisms. In other embodiments, some of LiDAR systems 110 and 120A-120M can share one or more components, thereby forming a distributed sensor system. In one example, optical fibers are used to deliver laser light from a centralized laser source to all LiDAR systems. For instance, system 110 (or another system that is centrally positioned or positioned anywhere inside the vehicle 100) includes a light source, a transmitter, and a light detector, but has no steering mechanisms. System 110 may distribute transmission light to each of systems 120A-120M. The transmission light may be distributed via optical fibers. Optical connectors can be used to couple the optical fibers to each of system 110 and 120A-120M. In some examples, one or more of systems 120A-120M include steering mechanisms but no light sources, transmitters, or light detectors. A steering mechanism may include one or more moveable mirrors such as one or more polygon mirrors, one or more single plane mirrors, one or more multi-plane mirrors, or the like. Embodiments of the light source, transmitter, steering mechanism, and light detector are described in more detail below. Via the steering mechanisms, one or more of systems 120A-120M scan light into one or more respective FOVs and receive corresponding return light. The return light is formed by scattering or reflecting the transmissionAttorney Docket Number: 11325.10209W001light by one or more objects in the FOVs. Systems 120A-120M may also include collection lens and / or other optics to focus and / or direct the return light into optical fibers, which deliver the received return light to system 110. System 110 includes one or more light detectors for detecting the received return light. In some examples, system 110 is disposed inside a vehicle such that it is in a temperature-controlled environment, while one or more systems 120A-120M may be at least partially exposed to the external environment.

[0050] FIG. 2A is a block diagram 200A illustrating interactions between vehicle onboard LiDAR system(s) 210 and multiple other systems including a vehicle perception and planning system 220. LiDAR system(s) 210 can be mounted on or integrated to a vehicle. LiDAR system(s) 210 include sensor(s) that scan laser light to the surrounding environment to measure the distance, angle, and / or velocity of objects. Based on the scattered light that returned to LiDAR system(s) 210, it can generate sensor data (e.g., image data or 3D point cloud data) representing the perceived external environment.

[0051] LiDAR system(s) 210 can include one or more of short-range LiDAR sensors, mediumrange LiDAR sensors, and long-range LiDAR sensors. A short-range LiDAR sensor measures objects located up to about 20-50 meters from the LiDAR sensor. Short-range LiDAR sensors can be used for, e.g., monitoring nearby moving objects (e.g., pedestrians crossing street in a school zone), parking assistance applications, or the like. A medium-range LiDAR sensor measures objects located up to about 70-200 meters from the LiDAR sensor. Medium-range LiDAR sensors can be used for, e.g., monitoring road intersections, assistance for merging onto or leaving a freeway, or the like. A long-range LiDAR sensor measures objects located up to about 200 meters and beyond. Long-range LiDAR sensors are typically used when a vehicle is travelling at a high speed (e.g., on a freeway), such that the vehicle’s control systems may only have a few seconds (e.g., 6-8 seconds) to respond to any situations detected by the LiDAR sensor. As shown in FIG. 2A, in one embodiment, the LiDAR sensor data can be provided to vehicle perception and planning system 220 via a communication path 213 for further processing and controlling the vehicle operations. Communication path 213 can be any wired or wireless communication links that can transfer data.

[0052] With reference still to FIG. 2A, in some embodiments, other vehicle onboard sensor(s) 230 are configured to provide additional sensor data separately or together with LiDARAttorney Docket Number: 11325.10209W001system(s) 210. Other vehicle onboard sensors 230 may include, for example, one or more camera(s) 232, one or more radar(s) 234, one or more ultrasonic sensor(s) 236, and / or other sensor(s) 238. Camera(s) 232 can take images and / or videos of the external environment of a vehicle. Camera(s) 232 can take, for example, high-definition (HD) videos having millions of pixels in each frame. A camera includes image sensors that facilitate producing monochrome or color images and videos. Color information may be important in interpreting data for some situations (e.g., interpreting images of traffic lights). Color information may not be available from other sensors such as LiDAR or radar sensors. Camera(s) 232 can include one or more of narrow-focus cameras, wider-focus cameras, side-facing cameras, infrared cameras, fisheye cameras, or the like. The image and / or video data generated by camera(s) 232 can also be provided to vehicle perception and planning system 220 via communication path 233 for further processing and controlling the vehicle operations. Communication path 233 can be any wired or wireless communication links that can transfer data. Camera(s) 232 can be mounted on, or integrated to, a vehicle at any location (e.g., rear-view mirrors, pillars, front grille, and / or back bumpers, etc.).

[0053] Other vehicle onboard sensor(s) 230 can also include radar sensor(s) 234. Radar sensor(s) 234 use radio waves to determine the range, angle, and velocity of objects. Radar sensor(s) 234 produce electromagnetic waves in the radio or microwave spectrum. The electromagnetic waves reflect off an object and some of the reflected waves return to the radar sensor, thereby providing information about the object’s position and velocity. Radar sensor(s) 234 can include one or more of short-range radar(s), medium-range radar(s), and long-range radar(s). A short-range radar measures objects located at about 0.1-30 meters from the radar. A short-range radar is useful in detecting objects located near the vehicle, such as other vehicles, buildings, walls, pedestrians, bicyclists, etc. A short-range radar can be used to detect a blind spot, assist in lane changing, provide rear-end collision warning, assist in parking, provide emergency braking, or the like. A medium -range radar measures objects located at about 30-80 meters from the radar. A long-range radar measures objects located at about 80-200 meters. Medium- and / or long-range radars can be useful in, for example, traffic following, adaptive cruise control, and / or highway automatic braking. Sensor data generated by radar sensor(s) 234 can also be provided to vehicle perception and planning system 220 via communication path 233 for further processing and controlling the vehicle operations. Radar sensor(s) 234 can beAttorney Docket Number: 11325.10209W001mounted on, or integrated to, a vehicle at any location (e.g., rear-view mirrors, pillars, front grille, and / or back bumpers, etc.).

[0054] Other vehicle onboard sensor(s) 230 can also include ultrasonic sensor(s) 236. Ultrasonic sensor(s) 236 use acoustic waves or pulses to measure objects located external to a vehicle. The acoustic waves generated by ultrasonic sensor(s) 236 are transmitted to the surrounding environment. At least some of the transmitted waves are reflected off an object and return to the ultrasonic sensor(s) 236. Based on the return signals, a distance of the object can be calculated. Ultrasonic sensor(s) 236 can be useful in, for example, checking blind spots, identifying parking spaces, providing lane changing assistance into traffic, or the like. Sensor data generated by ultrasonic sensor(s) 236 can also be provided to vehicle perception and planning system 220 via communication path 233 for further processing and controlling the vehicle operations.Ultrasonic sensor(s) 236 can be mounted on, or integrated to, a vehicle at any location (e.g., rearview mirrors, pillars, front grille, and / or back bumpers, etc.).

[0055] In some embodiments, one or more other sensor(s) 238 may be attached in a vehicle and may also generate sensor data. Other sensor(s) 238 may include, for example, global positioning systems (GPS), inertial measurement units (1MU), or the like. Sensor data generated by other sensor(s) 238 can also be provided to vehicle perception and planning system 220 via communication path 233 for further processing and controlling the vehicle operations. It is understood that communication path 233 may include one or more communication links to transfer data between the various sensor(s) 230 and vehicle perception and planning system 220.

[0056] In some embodiments, as shown in FIG. 2A, sensor data from other vehicle onboard sensor(s) 230 can be provided to vehicle onboard LiDAR system(s) 210 via communication path 231. LiDAR system(s) 210 may process the sensor data from other vehicle onboard sensor(s) 230. For example, sensor data from camera(s) 232, radar sensor(s) 234, ultrasonic sensor(s) 236, and / or other sensor(s) 238 may be correlated or fused with sensor data from LiDAR system(s) 210, thereby at least partially offloading the sensor fusion process performed by vehicle perception and planning system 220. It is understood that other configurations may also be implemented for transmitting and processing sensor data from the various sensors (e.g., data can be transmitted to a cloud or edge computing service provider for processing and then theAttorney Docket Number: 11325.10209W001processing results can be transmitted back to the vehicle perception and planning system 220 and / or LiDAR system 210).

[0057] With reference still to FIG. 2A, in some embodiments, sensors onboard other vehicle(s) 250 are used to provide additional sensor data separately or together with LiDAR system(s) 210. For example, two or more nearby vehicles may have their own respective LiDAR sensor(s), camera(s), radar sensor(s), ultrasonic sensor(s), etc. Nearby vehicles can communicate and share sensor data with one another. Communications between vehicles are also referred to as V2V (vehicle to vehicle) communications. For example, as shown in FIG. 2A, sensor data generated by other vehicle(s) 250 can be communicated to vehicle perception and planning system 220 and / or vehicle onboard LiDAR system(s) 210, via communication path 253 and / or communication path 251, respectively. Communication paths 253 and 251 can be any wired or wireless communication links that can transfer data.

[0058] Sharing sensor data facilitates a better perception of the environment external to the vehicles. For instance, a first vehicle may not sense a pedestrian that is behind a second vehicle but is approaching the first vehicle. The second vehicle may share the sensor data related to this pedestrian with the first vehicle such that the first vehicle can have additional reaction time to avoid collision with the pedestrian. In some embodiments, similar to data generated by sensor(s) 230, data generated by sensors onboard other vehicle(s) 250 may be correlated or fused with sensor data generated by LiDAR system(s) 210 (or with other LiDAR systems located in other vehicles), thereby at least partially offloading the sensor fusion process performed by vehicle perception and planning system 220.

[0059] In some embodiments, intelligent infrastructure system(s) 240 are used to provide sensor data separately or together with LiDAR system(s) 210. Certain infrastructures may be configured to communicate with a vehicle to convey information and vice versa.Communications between a vehicle and infrastructures are generally referred to as V2I (vehicle to infrastructure) communications. For example, intelligent infrastructure system(s) 240 may include an intelligent traffic light that can convey its status to an approaching vehicle in a message such as “changing to yellow in 5 seconds.” Intelligent infrastructure system(s) 240 may also include its own LiDAR system mounted near an intersection such that it can convey traffic monitoring information to a vehicle. For example, a left-turning vehicle at an intersection mayAttorney Docket Number: 11325.10209W001not have sufficient sensing capabilities because some of its own sensors may be blocked by traffic in the opposite direction. In such a situation, sensors of intelligent infrastructure system(s) 240 can provide useful data to the left-turning vehicle. Such data may include, for example, traffic conditions, information of objects in the direction the vehicle is turning to, traffic light status and predictions, or the like. These sensor data generated by intelligent infrastructure system(s) 240 can be provided to vehicle perception and planning system 220 and / or vehicle onboard LiDAR system(s) 210, via communication paths 243 and / or 241, respectively.Communication paths 243 and / or 241 can include any wired or wireless communication links that can transfer data. For example, sensor data from intelligent infrastructure system(s) 240 may be transmitted to LiDAR system(s) 210 and correlated or fused with sensor data generated by LiDAR system(s) 210, thereby at least partially offloading the sensor fusion process performed by vehicle perception and planning system 220. V2V and V2I communications described above are examples of vehicle-to-X (V2X) communications, where the “X” represents any other devices, systems, sensors, infrastructure, or the like that can share data with a vehicle.

[0060] With reference still to FIG. 2A, via various communication paths, vehicle perception and planning system 220 receives sensor data from one or more of LiDAR system(s) 210, other vehicle onboard sensor(s) 230, other vehicle(s) 250, and / or intelligent infrastructure system(s) 240. In some embodiments, different types of sensor data are correlated and / or integrated by a sensor fusion sub-system 222. For example, sensor fusion sub-system 222 can generate a 360-degree model using multiple images or videos captured by multiple cameras disposed at different positions of the vehicle. Sensor fusion sub-system 222 obtains sensor data from different types of sensors and uses the combined data to perceive the environment more accurately. For example, a vehicle onboard camera 232 may not capture a clear image because it is facing the Sun or a light source (e.g., another vehicle’s headlight during nighttime) directly. A LiDAR system 210 may not be affected as much and therefore sensor fusion sub-system 222 can combine sensor data provided by both camera 232 and LiDAR system 210, and use the sensor data provided by LiDAR system 210 to compensate the unclear image captured by camera 232. As another example, in a rainy or foggy weather, a radar sensor 234 may work better than a camera 232 or a LiDAR system 210. Accordingly, sensor fusion sub-system 222 may use sensor data provided by the radar sensor 234 to compensate the sensor data provided by camera 232 or LiDAR system 210.Attorney Docket Number: 11325.10209W001

[0061] In other examples, sensor data generated by other vehicle onboard sensor(s) 230 may have a lower resolution (e.g., radar sensor data) and thus may need to be correlated and confirmed by LiDAR system(s) 210, which usually has a higher resolution. For example, a sewage cover (also referred to as a manhole cover) may be detected by radar sensor 234 as an object towards which a vehicle is approaching. Due to the low-resolution nature of radar sensor 234, vehicle perception and planning system 220 may not be able to determine whether the object is an obstacle that the vehicle needs to avoid. High-resolution sensor data generated by LiDAR system(s) 210 thus can be used to correlated and confirm that the object is a sewage cover and causes no harm to the vehicle.

[0062] Vehicle perception and planning system 220 further comprises an object classifier 223. Using raw sensor data and / or correlated / fused data provided by sensor fusion sub-system 222, object classifier 223 can use any computer vision techniques to detect and classify the objects and estimate the positions of the objects. In some embodiments, object classifier 223 can use machine-learning based techniques to detect and classify objects. Examples of the machinelearning based techniques include utilizing algorithms such as region-based convolutional neural networks (R-CNN), Fast R-CNN, Faster R-CNN, histogram of oriented gradients (HOG), region-based fully convolutional network (R-FCN), single shot detector (SSD), spatial pyramid pooling (SPP-net), and / or You Only Look Once (Yolo).

[0063] Vehicle perception and planning system 220 further comprises a road detection subsystem 224. Road detection sub-system 224 localizes the road and identifies objects and / or markings on the road. For example, based on raw or fused sensor data provided by radar sensor(s) 234, camera(s) 232, and / or LiDAR system(s) 210, road detection sub-system 224 can build a 3D model of the road based on machine-learning techniques (e.g., pattern recognition algorithms for identifying lanes). Using the 3D model of the road, road detection sub-system 224 can identify objects (e.g., obstacles or debris on the road) and / or markings on the road (e.g., lane lines, turning marks, crosswalk marks, or the like).

[0064] Vehicle perception and planning system 220 further comprises a localization and vehicle posture sub-system 225. Based on raw or fused sensor data, localization and vehicle posture sub-system 225 can determine position of the vehicle and the vehicle’s posture. For example, using sensor data from LiDAR system(s) 210, camera(s) 232, and / or GPS data, localization andAttorney Docket Number: 11325.10209W001vehicle posture sub-system 225 can determine an accurate position of the vehicle on the road and the vehicle’s six degrees of freedom (e.g., whether the vehicle is moving forward or backward, up or down, and left or right). In some embodiments, high-definition (HD) maps are used for vehicle localization. HD maps can provide highly detailed, three-dimensional, computerized maps that pinpoint a vehicle’s location. For instance, using the HD maps, localization and vehicle posture sub-system 225 can determine precisely the vehicle’s current position (e.g., which lane of the road the vehicle is currently in, how close it is to a curb or a sidewalk) and predict vehicle’s future positions.

[0065] Vehicle perception and planning system 220 further comprises obstacle predictor 226. Objects identified by object classifier 223 can be stationary (e.g., a light pole, a road sign) or dynamic (e.g., a moving pedestrian, bicycle, another car). For moving objects, predicting their moving path or future positions can be important to avoid collision. Obstacle predictor 226 can predict an obstacle trajectory and / or warn the driver or the vehicle planning sub-system 228 about a potential collision. For example, if there is a high likelihood that the obstacle’s trajectory intersects with the vehicle’s current moving path, obstacle predictor 226 can generate such a warning. Obstacle predictor 226 can use a variety of techniques for making such a prediction. Such techniques include, for example, constant velocity or acceleration models, constant turn rate and velocity / accel eration models, Kalman Filter and Extended Kalman Filter based models, recurrent neural network (RNN) based models, long short-term memory (LSTM) neural network based models, encoder-decoder RNN models, or the like.

[0066] With reference still to FIG. 2A, in some embodiments, vehicle perception and planning system 220 further comprises vehicle planning sub-system 228. Vehicle planning sub-system 228 can include one or more planners such as a route planner, a driving behaviors planner, and a motion planner. The route planner can plan the route of a vehicle based on the vehicle’s current location data, target location data, traffic information, etc. The driving behavior planner adjusts the timing and planned movement based on how other objects might move, using the obstacle prediction results provided by obstacle predictor 226. The motion planner determines the specific operations the vehicle needs to follow. The planning results are then communicated to vehicle control system 280 via vehicle interface 270. The communication can be performed through communication paths 227 and 271, which include any wired or wireless communication links that can transfer data.Attorney Docket Number: 11325.10209W001

[0067] Vehicle control system 280 controls the vehicle’s steering mechanism, throttle, brake, etc., to operate the vehicle according to the planned route and movement. In some examples, vehicle perception and planning system 220 may further comprise a user interface 260, which provides a user (e.g., a driver) access to vehicle control system 280 to, for example, override or take over control of the vehicle when necessary. User interface 260 may also be separate from vehicle perception and planning system 220. User interface 260 can communicate with vehicle perception and planning system 220, for example, to obtain and display raw or fused sensor data, identified objects, vehicle’s location / posture, etc. These displayed data can help a user to better operate the vehicle. User interface 260 can communicate with vehicle perception and planning system 220 and / or vehicle control system 280 via communication paths 221 and 261 respectively, which include any wired or wireless communication links that can transfer data. It is understood that the various systems, sensors, communication links, and interfaces in FIG. 2A can be configured in any desired manner and not limited to the configuration shown in FIG. 2A.

[0068] FIG. 2B is a block diagram 200B illustrating interactions between robot central system 242 and multiple other systems including sensors 212, actuators 252, user interface 262 and facility network 272. At least some of the systems shown in FIG. 2B can be mounted to, or integrated with, a robot. A robot can be, for example, an industrial robot, an autonomous robot, a medical robot, a service robot, a military robot, an aquatic robot, an entertainment robot, a construction robot, or any other type of robot. The sensors 212 can include various sensors mounted to, or integrated with, a robot. As shown in FIG. 2B, sensor data can be provided to a robot central system 242 via a communication path 217 for further processing and controlling the robot operations. Communication path 217 can be any wired or wireless communication links that can transfer data. It is understood that communication path 217 may include one or more communication links to transfer data between the sensors 212 and robot central system 242.

[0069] As shown in FIG. 2B, the sensors 212 can include robot cameras 214, robot LiDARs 215, and robot other sensors 216. Robot cameras 214 can take images and / or videos of the external environment of a robot. Similar to camera(s) 232 shown in FIG. 2 A, robot cameras 214 can take, for example, images and / or high-definition (HD) videos having millions of pixels, or higher, in each frame. A robot camera 214 can include image sensors that facilitate producing monochrome or color images and videos. Color information may be used for a robot to identify and track specific objects based on their colors. Color information may not be available fromAttorney Docket Number: 11325.10209W001other sensors such as LiDAR or radar sensors. Robot cameras 214 can include one or more of narrow-focus cameras, wider-focus cameras, side-facing cameras, infrared cameras, fisheye cameras, or the like. The image and / or video data generated by robot cameras 214 can be provided to robot central system 242 via communication path 217 for further processing and controlling the robot operations.

[0070] Robot LiDARs 215 can be LiDAR system(s) mounted on or integrated to the robot.Robot LiDARs 215 can transmit laser light to the surrounding environment to measure the distance, angle, and / or velocity of objects. Robot LiDAR 215 can be a LiDAR system that has mechanical scanning components or a system that has no mechanical scanning components (e.g., a flash LiDAR). The transmitted laser light may be scattered or reflected (for simplicity) to form the return light. Based on the return light received by robot LiDARs 215, it can generate sensor data (e.g., image data or 3D point cloud data) representing the perceived external environment. Robot LiDARs 215 can include one or more of short-range LiDAR sensors and medium-range LiDAR sensors. Short-range robot LiDAR sensors can be used for creating a detailed 3D map for the robot’s surrounding environment, and detecting nearby obstacles (e.g., walls, furniture, and small objects close to the ground, or the like) to facilitate safe navigation and collision avoidance. Medium-range robot LiDARs can be used for robots operating in moderately sized environments like offices, small to mid-sized warehouses, or production areas. As shown in FIG. 2B, in one embodiment, the LiDAR sensor data can also be provided to robot central system 242 via a communication path 217 for further processing and controlling the robot operations.

[0071] Robot other sensors 216 can be other sensors configured to provide additional sensor data separately or together with robot cameras 214 and robot LiDARs 215. Robot other sensors 216 may include, for example, radar sensors, ultrasound sensors, depth sensors, IMU, accelerometers, tactile sensors, or the like. Sensor data generated by robot other sensors 216 can also be provided to robot central system 242 via communication path 217 for further processing and controlling the robot operations.

[0072] As shown in FIG. 2B, robot central system 242 includes sensor data streaming subsystem 244. Sensor data streaming sub-system 244 is configured to continuously and transmit data in real time to a processing unit in robots (e.g., 3D perception and localization sub-systemAttorney Docket Number: 11325.10209W001245, task management sub-system 246, action planning sub-system 247, and / or network subsystem 248) or a remote system (e.g., network system 248 can also be a remote system). In some embodiments, via communication path 217, sensor data streaming sub-system 244 collects raw sensor data (e.g., image data, video data, 3D point cloud data, or other sensor data) from sensors 212 in a continuous stream to the processing units (e.g., Processor 610). Then in the processing units, the streamed data can undergo various processing steps, including filtering, transformation, and analysis using specialized algorithms. These involve sensor data fusion, object detection and recognition, and localization and mapping. Therefore, the streamed data transmitted by sensor data streaming sub-system 244 enables robots to perceive their environment, understand their own state, and make informed decisions for autonomous operation. In some examples, the realtime transmission performed by sensor data streaming sub-system 244 can be required for the robot to perform tasks requiring immediate responses, such as obstacle avoidance or precise manipulation.

[0073] Robot central system 242 further includes 3D perception and localization sub-system 245. Using raw sensor data and / or fused data collected from sensors 212, 3D perception and localization sub-system 245 can understand a robot’s environment and determine the robot’s position and orientation within an environment. For example, by using sensor data from robot cameras 214, robot LiDARs 215, and / or robot other sensors 216 (e.g., depth sensor, IMU, etc.), 3D perception and localization sub-system 245 can percept and track immediate surrounding objects to build a map of an unknown environment. By using localization algorithms to process the sensor data, 3D perception and localization sub-system 245 can determine a robot’s position and orientation relative to its starting point or a place in the map of the robot’s location. As the robot moves, 3D perception and localization sub-system 245 can also update the robot’s location and refine the map of the environment.

[0074] As shown in FIG. 2B, robot central system 242 further includes task management subsystem 246. Task management sub-system 246 is configured to define, prioritize, schedule, and execute tasks for one or more robots to achieve a specific goal. For example, task management sub-system 246 can identify and understand requirements of tasks to make a task plan. Task management sub-system 246 can also break down a complex task into a logical order of multi-step actions to avoid execution failures. Task management sub-system 246 can also assign tasks to multiple robots and optimize the assignments to ensure more important tasks are handled first.Attorney Docket Number: 11325.10209W001Task management sub-system 246 can also perform real-time tracking of task progress and performance.

[0075] With reference still to FIG. 2B, in some embodiments, robot central system 242 further includes action planning sub-system 247. Action planning sub-system 247 is configured to interpret high-level task commands, reasoning about the environment, and translate abstract tasks into a sequence of low-level actions. By using the 3D perception and localization results provided by 3D perception and localization sub-system 245, action planning sub-system 247 can build an abstract understanding of environments by inferring the robot's current state and relationships between objects. Action planning sub-system 247 can also use task management results provided by task management sub-system 246, and convert each abstract task into a detailed, collision-free path or action for robot’s arms or wheel. As shown in FIG. 2B, data for the detailed paths or actions can be provided to actuators 252 via a communication path 257. Communication path 257 can be any wired or wireless communication links that can transfer data.

[0076] As shown in FIG. 2B, robot central system 242 further includes network sub-system 248. Network sub-system 248 is an interconnected network configured to connect the robot with robot central system 242 to other robots, human operators, and other facilities. Network sub-system 248 is also configured to connect robot central system 242 to a cloud or edge computing service provider, so that sensor data can be transmitted to the computing service provider for processing, and then the processing results can be transmitted back to the robot central system 242. In one example, the network sub-system 248 can include a network interface 680 of apparatus 600. One or more systems or sub-systems of the robot central system 242 described above can be implemented using the apparatus 600.

[0077] Actuators 252 are devices configured to enable robots to move, lift, and manipulate objects. As shown in FIG. 2B, actuators 252 includes wheel system 254, robot arm or other actuator system 255, and sensor gimbals or other sensor movement system 256. Wheel system 254 is a propulsion system for robots to drive, steer, and navigate. Wheel system 254 includes actuators (e.g., electric motors) configured to convert a source of energy (electrical, hydraulic, or pneumatic energy) into a mechanical force to spin robot’s wheels. Wheel system 254 also includes wheels and transmission configured to transmit the mechanical force from the actuatorsAttorney Docket Number: 11325.10209W001to the ground to enable robots to move. Based on results provided by action planning subsystem 247, the transmission can also modify the actuators' output to provide the necessary speed and torque for an intended task.

[0078] Robot arm or other actuator system 255 are actuators configured to move a robot’s arm or other moving part to perform tasks and manipulate objects. The actuators in robot arm or other actuator system 255 receive a low-energy input signal (e.g., an electrical current, compressed air, or hydraulic fluid) and convert the low-energy input into mechanical output, such as a rotary or linear motion for the arm. In some embodiments, robot central system 242 sends signals to the actuators of robot arm or other actuator system 255 via the communication path 257. Then robot arm or other actuator system 255 executes programmed instructions to move the arm to a desired position. Sensors 212 can also provide feedback on the arm's position and forces, then the robot central system 242 can adjust and refine movements of the arm.

[0079] Sensor gimbals or other sensor movement system 256 are actuators configured to stabilize and precisely orients sensors 212, regardless of a robot's own movement. Sensor gimbals or other sensor movement system 256 can be a required component for applications requiring steady, accurate data collection from a mobile or dynamic robot. Sensor gimbals or other sensor movement system 256 can include, for example, gimbal mechanisms, IMU, actuators, and a control unit. Gimbal mechanisms are a series of nested, pivoted rings that allow an attached sensor to rotate freely around one or more orthogonal axes (pitch, yaw, and roll). IMU includes gyroscopes, accelerometers, etc. The IMU detects and measures the system's orientation, angular velocity, and acceleration in real-time. Based on commands received from the control unit, actuators can counteract any unwanted movement detected by the IMU, and constantly adjust the sensor's position to maintain a desired orientation.

[0080] As shown in FIG. 2B, user interface 262 can be a separate system from robot central system 242. User interface 262 can communicate with robot central system 242 via communication path 263. The communication path 263 includes any wired or wireless communication links that can transfer data. User interface 262 can communicate with robot central system 242, for example, to obtain and display raw or fused sensor data, a robot’s surround environments, task management results, detailed actions or paths, etc.Attorney Docket Number: 11325.10209W001

[0081] With reference still to FIG. 2B, facility network 272 is a communication infrastructure that enables a collection of robots, sensors, controllers, and other devices to work together to achieve common goals. Network sub-system 248 can communicate with facility network 272 via communication path 273. The communication path 273 includes any wired or wireless communication links that can transfer data.

[0082] FIG. 3 is a block diagram illustrating an example LiDAR system 300. LiDAR system 300 can be used to implement LiDAR systems 110, 120A-120M, and / or 210 shown in FIGs. 1 and 2. In one embodiment, LiDAR system 300 comprises a light source 310, a transmitter 320, an optical receiver and light detector 330, a beam scanner 340, and control circuitry 350. These components are coupled together using communications paths 312, 314, 322, 332, 342, 352, 362, and 372. These communications paths include communication links (wired or wireless, bidirectional or unidirectional) among the various LiDAR system components, but need not be physical components themselves. While the communications paths can be implemented by one or more electrical wires, buses, or optical fibers, the communication paths can also be wireless channels or free-space optical paths so that no physical communication medium is present. For example, in one embodiment of LiDAR system 300, communication path 314 between light source 310 and transmitter 320 may be implemented using one or more optical fibers.Communication paths 332 and 352 may represent optical paths implemented using free space optical components and / or optical fibers. And communication paths 312, 322, 342, and 362 may be implemented using one or more electrical wires that carry electrical signals. The communications paths can also include one or more of the above types of communication mediums (e.g., they can include an optical fiber and a free-space optical component, or include one or more optical fibers and one or more electrical wires).

[0083] In some embodiments, LiDAR system 300 can be a coherent LiDAR system. One example is a frequency-modulated continuous-wave (FMCW) LiDAR. Coherent LiDARs detect objects by mixing return light from the objects with light from the coherent laser transmitter. Thus, as shown in FIG. 3, if LiDAR system 300 is a coherent LiDAR, it may include a route 372 providing a portion of transmission light from transmitter 320 to optical receiver and light detector 330. Route 372 may include one or more optics (e.g., optical fibers, lens, mirrors, etc.) for providing the light from transmitter 320 to optical receiver and light detector 330. The transmission light provided by transmitter 320 may be modulated light and can be split into twoAttorney Docket Number: 11325.10209W001portions. One portion is transmitted to the FOV, while the second portion is sent to the optical receiver and light detector 330 of the LiDAR system 300. The second portion is also referred to as the light that is kept local (LO) to the LiDAR system 300. The transmission light is scattered or reflected by various objects in the FOV and at least a portion of it forms return light. The return light is subsequently detected and interferometrically recombined with the second portion of the transmission light that was kept local. Coherent LiDAR provides a means of optically sensing an object’s range as well as its relative velocity along the line-of-sight (LOS).

[0084] LiDAR system 300 can also include other components not depicted in FIG. 3, such as power buses, power supplies, LED indicators, switches, etc. Additionally, other communication connections among components may be present, such as a direct connection between light source 310 and optical receiver and light detector 330 to provide a reference signal so that the time from when a light pulse is transmitted until a return light pulse is detected can be accurately measured.

[0085] Light source 310 outputs laser light for illuminating objects in a field of view (FOV). The laser light can be infrared light having a wavelength in the range of 700 nm to 1mm. Light source 310 can be, for example, a semiconductor-based laser (e.g., a diode laser) and / or a fiberbased laser. A semiconductor-based laser can be, for example, an edge emitting laser (EEL), a vertical cavity surface emitting laser (VCSEL), an external-cavity diode laser, a vertical-extemal-cavity surface-emitting laser, a distributed feedback (DFB) laser, a distributed Bragg reflector (DBR) laser, an interband cascade laser, a quantum cascade laser, a quantum well laser, a double heterostructure laser, or the like. A fiber-based laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium, and / or holmium. In some embodiments, a fiber laser is based on double-clad fibers, in which the gain medium forms the core of the fiber surrounded by two layers of cladding. The double-clad fiber allows the core to be pumped with a high-power beam, thereby enabling the laser source to be a high power fiber laser source.

[0086] In some embodiments, light source 310 comprises a master oscillator (also referred to as a seed laser) and power amplifier (MOP A). The power amplifier amplifies the output power of the seed laser. The power amplifier can be a fiber amplifier, a bulk amplifier, or a semiconductor optical amplifier. The seed laser can be a diode laser (e.g., a Fabry-Perot cavity laser, a distributed feedback laser), a solid-state bulk laser, or a tunable external-cavity diode laser. InAttorney Docket Number: 11325.10209W001some embodiments, light source 310 can be an optically pumped microchip laser. Microchip lasers are alignment-free monolithic solid-state lasers where the laser crystal is directly contacted with the end mirrors of the laser resonator. A microchip laser is typically pumped with a laser diode (directly or using a fiber) to obtain the desired output power. A microchip laser can be based on neodymium-doped yttrium aluminum garnet (Y3AI5O12) laser crystals (i.e., Nd:YAG), or neodymium-doped vanadate (i.e., NDiYVCh) laser crystals. In some examples, light source 310 may have multiple amplification stages to achieve a high power gain such that the laser output can have high power, thereby enabling the LiDAR. system to have a long scanning range. In some examples, the power amplifier of light source 310 can be controlled such that the power gain can be varied to achieve any desired laser output power.

[0087] FIG. 4A is a block diagram illustrating an example fiber-based laser source 400 having a seed laser and one or more pumps (e.g., laser diodes) for pumping desired output power. Fiberbased laser source 400 is an example of light source 310 depicted in FIG. 3. In some embodiments, fiber-based laser source 400 comprises a seed laser 402 configured to generate initial light pulses of one or more wavelengths (e.g., infrared wavelengths such as 1550 nm), which are provided to a wavelength-division multiplexor (WDM) 404 via an optical fiber 403. Fiber-based laser source 400 further comprises a pump 406 for providing laser power (e.g., of a different wavelength, such as 980 nm) to WDM 404 via an optical fiber 405. WDM 404 multiplexes the light pulses provided by seed laser 402 and the laser power provided by pump 406 onto a single optical fiber 407. The output of WDM 404 can then be provided to one or more pre-amplifier(s) 408 via optical fiber 407. Pre-amplifier(s) 408 can be optical amplifier(s) that amplify optical signals (e.g., with about 10-30 dB gain). In some embodiments, preamplifiers) 408 are low noise amplifiers. Pre-amplifier(s) 408 output to an optical combiner 410 via an optical fiber 409. Combiner 410 combines the output laser light of pre-amplifier(s) 408 with the laser power provided by pump 412 via an optical fiber 411. Combiner 410 can combine optical signals having the same wavelength or different wavelengths. One example of a combiner is a WDM. Combiner 410 provides combined optical signals to a booster amplifier 414, which produces output light pulses via optical fiber 415. The booster amplifier 414 provides further amplification of the optical signals (e.g., another 20-40 dB). The output light pulses can then be transmitted to transmitter 320 and / or beam scanner 340 (shown in FIG. 3). It is understood that FIG. 4A illustrates one example configuration of fiber-based laser source 400.Attorney Docket Number: 11325.10209W001Laser source 400 can have many other configurations using different combinations of one or more components shown in FIG. 4A and / or other components not shown in FIG. 4A (e.g., other components such as power supplies, lens(es), filters, splitters, combiners, etc.).

[0088] In some variations, fiber-based laser source 400 can be controlled (e.g., by control circuitry 350) to produce pulses of different amplitudes based on the fiber gain profile of the fiber used in fiber-based laser source 400. Communication path 312 couples fiber-based laser source 400 to control circuitry 350 (shown in FIG. 3) so that components of fiber-based laser source 400 can be controlled by or otherwise communicate with control circuitry 350.Alternatively, fiber-based laser source 400 may include its own dedicated controller. Instead of control circuitry 350 communicating directly with components of fiber-based laser source 400, a dedicated controller of fiber-based laser source 400 communicates with control circuitry 350 and controls and / or communicates with the components of fiber-based laser source 400. Fiber-based laser source 400 can also include other components not shown, such as one or more power connectors, power supplies, and / or power lines.

[0089] FIG. 4B is a block diagram illustrating an example semiconductor-based laser source 440. Semiconductor-based laser source 440 is an example of light source 310 depicted in FIG. 3. In the example shown in FIG. 4B, laser source 440 is a Vertical -Cavity Surface-Emitting Laser (VCSEL), which is a type of semiconductor laser diode with a distinctive structure that allows it to emit light vertically from the surface of the chip, rather than through the edge of the chip like the edge-emitting laser (EEL) diodes. VCSELs have advantages like high-speed operation and easy integration into semiconductor devices. FIG. 4B shows a cross-sectional view of an example VCSEL 440. In this example, the VCSEL 440 includes a metal contact layer 442, an upper Bragg reflector 444, an active region 446, a lower Bragg reflector 448, a substrate 450, and another metal contact 452. In the VCSEL 440, the metal contacts 442 and 452 are for making electrical contacts so that electrical current and / or voltage can be provided to VCSEL 440 for generating laser light. The substrate layer 450 is a semiconductor substrate, which can be, for example, a gallium arsenide (GaAs) substrate. VCSEL 440 uses a laser resonator, which includes two distributed Bragg reflector (DBR) reflectors (i.e., upper Bragg reflector 444 and lower Bragg reflector 448) with an active region 446 sandwiched between the DBR reflectors. The active region 446 includes, for example, one or more quantum wells for the laser light generation. The planar DBR-reflectors can be mirrors having layers with alternating high andAttorney Docket Number: 11325.10209W001low refractive indices. Each layer has a thickness of a quarter of the laser wavelength in the material, yielding intensity reflectivities above e.g., 99%. High reflectivity mirrors in VCSELs can balance the short axial length of the gain region. In one example of VCSEL 440, the upper and lower DBR reflectors 444 and 448 can be doped as p-type and n-type materials, forming a diode junction. In another example, the p-type and n-type regions may be embedded between the reflectors, requiring a more complex semiconductor process to make electrical contact to the active region, but eliminating electrical power loss in the DBR structure. The active region 446 is sandwiched between the DBR reflectors 444 and 448 of the VCSEL 440. The active region is where the laser light generation occurs. The active region 446 typically has a quantum well or quantum dot structure, which contains the gain medium responsible for light amplification.When an electric current is applied to the active region 446, it generates photons by stimulated emission. The distance between the upper and lower DBR reflectors 444 and 448 defines the cavity length of the VCSEL 440. The cavity length in turn determines the wavelength of the emitted light and influences the laser's performance characteristics. When an electrical current is applied to the VCSEL 440, it generates light that bounces between the DBR reflectors 444 and 448 and exits the VCSEL 440 through, for example, the lower DBR reflector 448, producing a highly coherent and vertically emitted laser beam 454. VCSEL 440 can provide an improved beam quality, low threshold current, and the ability to produce single-mode or multi-mode output.

[0090] In some variations, VCSEL 440 can be controlled (e.g., by control circuitry 350) to produce pulses of different amplitudes. Communication path 312 couples VCSEL 440 to control circuitry 350 (shown in FIG. 3) so that components of VCSEL 440 can be controlled by or otherwise communicate with control circuitry 350. Alternatively, VCSEL 440 may include its own dedicated controller. Instead of control circuitry 350 communicating directly with components of VCSEL 440, a dedicated controller of VCSEL 440 communicates with control circuitry 350 and controls and / or communicates with the components of VCSEL 440. VCSEL 440 can also include other components not shown, such as one or more power connectors, power supplies, and / or power lines.

[0091] VCSEL 440 can be used to generate laser pulses or continuous wave (CW) lasers. To generate laser pulses, control circuitry 350 modulates the current supplied to the VCSEL 440. By rapidly turning the supply current on and off, pulses of laser light can be generated. The duration,Attorney Docket Number: 11325.10209W001repetition rate, and shape of the pulses can be controlled by adjusting the modulation parameters. As another example, VCSEL 440 can also be a mode-locked VCSEL that uses a combination of current modulation and optical feedback to obtain ultra-short pulses. The mode-locked VCSEL may also be controlled to synchronize the phases of the laser modes to produce very short and high-intensity pulses. As another example, VCSEL 440 can use Q-Switching techniques, which includes an optical switch in the laser cavity, temporarily blocking the lasing action and allows energy to build up in the cavity. When the switch is opened, a high-intensity pulse is emitted. As another example, VCSEL 440 can also have external modulation performed by an external modulator (not shown), such as an electro-optic or acousto-optic modulator. The external modulation can be used in combination with the VCSEL itself to create pulsed output. The external modulator can be used to control the pulse duration and repetition rate. The type of VCSEL used as at least a part of light source 310 depends on the application and the required pulse characteristics, such as pulse duration, repetition rate, and peak power.

[0092] Referencing FIG. 3, typical operating wavelengths of light source 310 comprise, for example, about 850 nm, about 905 nm, about 940 nm, about 1064 nm, and about 1550 nm. For laser safety, the upper limit of maximum usable laser power is set by the U.S. FDA (U.S. Food and Drug Administration) regulations. The optical power limit at 1550 nm wavelength is much higher than those of the other aforementioned wavelengths. Further, at 1550 nm, the optical power loss in a fiber is low. There characteristics of the 1550 nm wavelength make it more beneficial for long-range LiDAR applications. The amount of optical power output from light source 310 can be characterized by its peak power, average power, pulse energy, and / or the pulse energy density. The peak power is the ratio of pulse energy to the width of the pulse (e.g., full width at half maximum or FWHM). Thus, a smaller pulse width can provide a larger peak power for a fixed amount of pulse energy. A pulse width can be in the range of nanosecond or picosecond. The average power is the product of the energy of the pulse and the pulse repetition rate (PRR). As described in more detail below, the PRR represents the frequency of the pulsed laser light. In general, the smaller the time interval between the pulses, the higher the PRR. The PRR typically corresponds to the maximum range that a LiDAR system can measure. Light source 310 can be configured to produce pulses at high PRR to meet the desired number of data points in a point cloud generated by the LiDAR system. Light source 310 can also be configured to produce pulses at medium or low PRR to meet the desired maximum detection distance. WallAttorney Docket Number: 11325.10209W001plug efficiency (WPE) is another factor to evaluate the total power consumption, which may be a useful indicator in evaluating the laser efficiency. For example, as shown in FIG. 1, multiple LiDAR systems may be attached to a vehicle, which may be an electrical-powered vehicle or a vehicle otherwise having limited fuel or battery power supply. Therefore, high WPE and intelligent ways to use laser power are often among the important considerations when selecting and configuring light source 310 and / or designing laser delivery systems for vehicle-mounted LiDAR applications.

[0093] It is understood that the above descriptions provide non-limiting examples of a light source 310. Light source 310 can be configured to include many other types of light sources (e.g., laser diodes, short-cavity fiber lasers, solid-state lasers, and / or tunable external cavity diode lasers) that are configured to generate one or more light signals at various wavelengths. In some examples, light source 310 comprises amplifiers (e.g., pre-amplifiers and / or booster amplifiers), which can be a doped optical fiber amplifier, a solid-state bulk amplifier, and / or a semiconductor optical amplifier. The amplifiers are configured to receive and amplify light signals with desired gains.

[0094] With reference back to FIG. 3, LiDAR system 300 further comprises a transmitter 320. Light source 310 provides laser light (e.g., in the form of a laser beam) to transmitter 320. The laser light provided by light source 310 can be amplified laser light with a predetermined or controlled wavelength, pulse repetition rate, and / or power level. Transmitter 320 receives the laser light from light source 310 and transmits the laser light to beam scanner 340 with low divergence. In some embodiments, transmitter 320 can include, for example, optical components (e.g., lens, fibers, mirrors, etc.) for transmitting one or more laser beams to a field-of-view (FOV) directly or via beam scanner 340. While FIG. 3 illustrates transmitter 320 and beam scanner 340 as separate components, they may be combined or integrated as one system in some embodiments, beam scanner 340 is described in more detail below.

[0095] Laser beams provided by light source 310 may diverge as they travel to transmitter 320. Therefore, transmitter 320 often comprises a collimating lens or a lens group configured to collect the diverging laser beams and produce more parallel optical beams with reduced or minimum divergence. The collimated optical beams can then be further directed through various optics such as mirrors and lens. A collimating lens may be, for example, a single plano-convexAttorney Docket Number: 11325.10209W001lens or a lens group. The collimating lens can be configured to achieve any desired properties such as the beam diameter, divergence, numerical aperture, focal length, or the like. A beam propagation ratio or beam quality factor (also referred to as the M2factor) is used for measurement of laser beam quality. In many LiDAR applications, it is important to have good laser beam quality in the generated transmitting laser beam. The M2factor represents a degree of variation of a beam from an ideal Gaussian beam. Thus, the M2factor reflects how well a collimated laser beam can be focused on a small spot, or how well a divergent laser beam can be collimated. Therefore, light source 310 and / or transmitter 320 can be configured to meet, for example, a scan resolution requirement while maintaining the desired M2factor.

[0096] One or more of the light beams provided by transmitter 320 are scanned by beam scanner 340 to a FOV. Beam scanner 340 scans light beams in multiple dimensions (e.g., in both the horizontal and vertical dimension) to facilitate LiDAR system 300 to map the environment by generating a 3D point cloud. A horizontal dimension can be a dimension that is parallel to the horizon or a surface associated with the LiDAR system or a vehicle (e.g., a road surface). A vertical dimension is perpendicular to the horizontal dimension (i.e., the vertical dimension forms a 90-degree angle with the horizontal dimension). Beam scanner 340 will be described in more detail below. The laser light scanned to an FOV may be scattered or reflected by an object in the FOV. At least a portion of the scattered or reflected light forms return light that returns to LiDAR system 300. FIG. 3 further illustrates an optical receiver and light detector 330 configured to receive the return light. Optical receiver and light detector 330 comprises an optical receiver that is configured to collect the return light from the FOV. The optical receiver can include optics (e.g., lens, fibers, mirrors, etc.) for receiving, redirecting, focusing, amplifying, and / or filtering return light from the FOV. For example, the optical receiver often includes a collection lens (e.g., a single plano-convex lens or a lens group) to collect and / or focus the collected return light onto a light detector.

[0097] A light detector detects the return light focused by the optical receiver and generates current and / or voltage signals proportional to the incident intensity of the return light. Based on such current and / or voltage signals, the depth information of the object in the FOV can be derived. One example method for deriving such depth information is based on the direct TOF (time of flight), which is described in more detail below. A light detector may be characterized by its detection sensitivity, quantum efficiency, detector bandwidth, linearity, signal to noiseAttorney Docket Number: 11325.10209W001ratio (SNR), overload resistance, interference immunity, etc. Based on the applications, the light detector can be configured or customized to have any desired characteristics. For example, optical receiver and light detector 330 can be configured such that the light detector has a large dynamic range while having a good linearity. The light detector linearity indicates the detector’s capability of maintaining linear relationship between input optical signal power and the detector’s output. A detector having good linearity can maintain a linear relationship over a large dynamic input optical signal range.

[0098] To achieve desired detector characteristics, configurations or customizations can be made to the light detector’s structure and / or the detector’s material system. Various detector structures can be used for a light detector. For example, a light detector structure can be a PIN based structure, which has an undoped intrinsic semiconductor region (i.e., an “i” region) between a p-type semiconductor and an n-type semiconductor region. Other light detector structures comprise, for example, an APD (avalanche photodiode) based structure, a PMT (photomultiplier tube) based structure, a SiPM (Silicon photomultiplier) based structure, a SPAD (single-photon avalanche diode) based structure, and / or quantum wires. For material systems used in a light detector, Si, InGaAs, and / or Si / Ge based materials can be used. It is understood that many other detector structures and / or material systems can be used in optical receiver and light detector 330.

[0099] A light detector (e.g., an APD based detector) may have an internal gain such that the input signal is amplified when generating an output signal. However, noise may also be amplified due to the light detector’s internal gain. Common types of noise include signal shot noise, dark current shot noise, thermal noise, and amplifier noise. In some embodiments, optical receiver and light detector 330 may include a pre-amplifier that is a low noise amplifier (LNA). In some embodiments, the pre-amplifier may also include a transimpedance amplifier (TIA), which converts a current signal to a voltage signal. For a linear detector system, input equivalent noise or noise equivalent power (NEP) measures how sensitive the light detector is to weak signals. Therefore, they can be used as indicators of the overall system performance. For example, the NEP of a light detector specifies the power of the weakest signal that can be detected and therefore it in turn specifies the maximum range of a LiDAR system. It is understood that various light detector optimization techniques can be used to meet the requirement of LiDAR system 300. Such optimization techniques may include selecting different detector structures, materials, and / or implementing signal processing techniques (e.g.,Attorney Docket Number: 11325.10209W001filtering, noise reduction, amplification, or the like). For example, in addition to, or instead of, using direct detection of return signals (e.g., by using ToF), coherent detection can also be used for a light detector. Coherent detection allows for detecting amplitude and phase information of the received light by interfering the received light with a local oscillator. Coherent detection can improve detection sensitivity and noise immunity.

[0100] FIG. 3 further illustrates that LiDAR system 300 comprises beam scanner 340. As described above, beam scanner 340 directs light beams from transmitter 320 to scan an FOV in multiple dimensions. A beam scanner is also referred to as a steering mechanism, a raster mechanism, a scanning mechanism, or simply a light scanner. Scanning light beams in multiple directions (e.g., in both the horizontal and vertical directions) facilitates a LiDAR system to map the environment by generating an image or a 3D point cloud. A beam scanner can be based on mechanical scanning and / or solid-state scanning. Mechanical scanning uses one or more rotating mirrors, oscillating mirrors (such as Galvanometer mirrors), and Micro-Electro-Mechanical Systems (MEMS) mirrors to steer the laser beam or physically rotate the LiDAR transmitter and receiver (collectively referred to as transceiver) to scan the laser beam. Solid-state scanning directs the laser beam to various positions through the FOV without mechanically moving any macroscopic components such as the transceiver. Solid-state scanning include, for example, optical phased arrays based steering and flash LiDAR based steering. In some embodiments, because solid-state scanning does not physically move macroscopic components, the steering performed by a solid-state scanning may be referred to as electronic steering. A LiDAR system using solid-state scanning may also be referred to as a non-mechanical scanning or simply nonscanning LiDAR system (a flash LiDAR system is an example non-scanning LiDAR system).

[0101] Beam scanner 340 can be used with a transceiver (e.g., transmitter 320 and optical receiver and light detector 330) to scan the FOV for generating an image or a 3D point cloud. As an example, to implement beam scanner 340, a two-dimensional mechanical scanner can be used with a single-point or several single-point transceivers. A single-point transceiver transmits a single light beam or a small number of light beams (e.g., 2-8 beams) to the beam scanner 340. A two-dimensional mechanical beam scanner comprises, for example, polygon mirror(s), oscillating mirror(s), rotating prism(s), rotating tilt mirror surface(s), single-plane or multi-plane mirror(s), or a combination thereof. In some embodiments beam scanner 340 may include nonmechanical steering scanning such as solid-state steering scanning. For example, beam scannerAttorney Docket Number: 11325.10209W001340 can be based on tuning wavelength of the laser light combined with refraction effect, and / or based on reconfigurable grating / phase array. In some embodiments, beam scanner 340 can use a single scanning device to achieve two-dimensional scanning or multiple scanning devices combined to realize two-dimensional scanning.

[0102] As another example, to implement beam scanner 340, a one-dimensional mechanical scanner can be used with an array or a large number of single-point transceivers. Specifically, the transceiver array can be mounted on a rotating platform to achieve 360-degree horizontal field of view. Alternatively, a static transceiver array can be combined with the one-dimensional mechanical scanner. A one-dimensional mechanical scanner comprises polygon mirror(s), oscillating mirror(s), rotating prism(s), rotating tilt mirror surface(s), or a combination thereof, for obtaining a forward-looking horizontal field of view. Beam scanner using mechanical scanners can provide robustness and reliability in high volume production for automotive applications.

[0103] As another example, to implement beam scanner 340, a two-dimensional transceiver can be used to generate a scan image or a 3D point cloud directly. In some embodiments, a stitching or micro shift method can be used to improve the resolution of the scan image or the field of view being scanned. For example, using a two-dimensional transceiver, signals generated at one direction (e.g., the horizontal direction) and signals generated at the other direction (e.g., the vertical direction) may be integrated, interleaved, and / or matched to generate a higher or full resolution image or 3D point cloud representing the scanned FOV.

[0104] Some implementations of beam scanner 340 comprise one or more optical redirection elements (e.g., mirrors or lenses) that steer return light signals (e.g., by rotating, vibrating, or directing) along a receive path to direct the return light signals to optical receiver and light detector 330. The optical redirection elements that direct light signals along the transmitting and receiving paths may be the same components (e.g., shared), separate components (e.g., dedicated), and / or a combination of shared and separate components. This means that in some cases the transmitting and receiving paths are different although they may partially overlap (or in some cases, substantially overlap or completely overlap).

[0105] With reference still to FIG. 3, LiDAR system 300 further comprises control circuitry 350. Control circuitry 350 can be configured and / or programmed to control various parts of theAttorney Docket Number: 11325.10209W001LiDAR system 300 and / or to perform signal processing. Tn a typical system, control circuitry 350 can be configured and / or programmed to perform one or more control operations including, for example, controlling light source 310 to obtain the desired laser pulse timing, the pulse repetition rate, and power; controlling beam scanner 340 (e.g., controlling the speed, direction, and / or other parameters) to scan the FOV and maintain pixel registration and / or alignment; controlling optical receiver and light detector 330 (e.g., controlling the sensitivity, noise reduction, filtering, and / or other parameters) such that it is an optimal state; and monitoring overall system health / status for functional safety (e.g., monitoring the laser output power and / or the beam scanner operating status for safety).

[0106] Control circuitry 350 can also be configured and / or programmed to perform signal processing to the raw data generated by optical receiver and light detector 330 to derive distance and reflectance information, and perform data packaging and communication to vehicle perception and planning system 220 (shown in FIG. 2A). For example, control circuitry 350 determines the time it takes from transmitting a light pulse until a corresponding return light pulse is received; determines when a return light pulse is not received for a transmitted light pulse; determines the direction (e.g., horizontal and / or vertical information) for a transmitted / retum light pulse; determines the estimated range in a particular direction; derives the reflectivity of an object in the FOV, and / or determines any other type of data relevant to LiDAR system 300.

[0107] LiDAR system 300 can be disposed in a vehicle, which may operate in many different environments including hot or cold weather, rough road conditions that may cause intense vibration, high or low humidities, dusty areas, etc. Therefore, in some embodiments, optical and / or electronic components of LiDAR system 300 (e g., optics in transmitter 320, optical receiver and light detector 330, and beam scanner 340) are disposed and / or configured in such a manner to maintain long term mechanical and optical stability. For example, components in LiDAR system 300 may be secured and sealed such that they can operate under all conditions a vehicle may encounter. As an example, an anti-moisture coating and / or hermetic sealing may be applied to optical components of transmitter 320, optical receiver and light detector 330, and beam scanner 340 (and other components that are susceptible to moisture). As another example, housing(s), enclosure(s), fairing(s), and / or window can be used in LiDAR system 300 for providing desired characteristics such as hardness, ingress protection (IP) rating, self-cleaningAttorney Docket Number: 11325.10209W001capability, resistance to chemical and resistance to impact, or the like. In addition, efficient and economical methodologies for assembling LiDAR system 300 may be used to meet the LiDAR operating requirements while keeping the cost low.

[0108] It is understood by a person of ordinary skill in the art that FIG. 3 and the above descriptions are for illustrative purposes only, and a LiDAR system can include other functional units, blocks, or segments, and can include variations or combinations of these above functional units, blocks, or segments. For example, LiDAR system 300 can also include other components not depicted in FIG. 3, such as power buses, power supplies, LED indicators, switches, etc. Additionally, other connections among components may be present, such as a direct connection between light source 310 and optical receiver and light detector 330 so that light detector 330 can accurately measure the time from when light source 310 transmits a light pulse until light detector 330 detects a return light pulse.

[0109] These components shown in FIG. 3 are coupled together using communications paths 312, 314, 322, 332, 342, 352, 362, and 372. These communications paths represent communication paths (bidirectional or unidirectional) among the various LiDAR system components but need not be physical components themselves. While the communications paths can be implemented by one or more electrical wires, buses, or optical fibers, the communication paths can also be wireless channels or open-air optical paths so that no physical communication medium is present. For example, in one example LiDAR system, communication path 314 includes one or more optical fibers; communication path 352 represents an optical path; and communication paths 312, 322, 342, and 362 are all electrical wires that carry electrical signals. The communication paths can also include more than one of the above types of communication mediums (e.g., they can include an optical fiber and an optical path, or one or more optical fibers and one or more electrical wires).

[0110] As described above, some LiDAR systems use the time-of-flight (ToF) of light signals (e.g., light pulses) to determine the distance to objects in a light path. For example, with reference to FIG. 5A, an example LiDAR system 500 includes a laser light source (e.g., a fiber laser), a steering mechanism (e.g., a system of one or more moving mirrors), and a light detector (e.g., a photodetector with one or more optics). LiDAR system 500 can be implemented using, for example, LiDAR system 300 described above. LiDAR system 500 transmits a light pulseAttorney Docket Number: 11325.10209W001502 along light path 504 as determined by the steering mechanism of LiDAR system 500. In the depicted example, light pulse 502, which is generated by the laser light source, is a short pulse of laser light. Further, the signal steering mechanism of the LiDAR system 500 is a pulsed-signal steering mechanism. However, it should be appreciated that LiDAR systems can operate by generating, transmitting, and detecting light signals that are not pulsed and derive ranges to an object in the surrounding environment using techniques other than time-of-flight. For example, some LiDAR systems use frequency modulated continuous waves (i.e., “FMCW”). It should be further appreciated that any of the techniques described herein with respect to time-of-flight based systems that use pulsed signals also may be applicable to LiDAR systems that do not use one or both of these techniques.

[0111] Referring back to FIG. 5 A (e.g., illustrating a time-of-flight LiDAR system that uses light pulses), when light pulse 502 reaches object 506, light pulse 502 scatters or reflects to form a return light pulse 508. Return light pulse 508 may return to system 500 along light path 510. The time from when transmitted light pulse 502 leaves LiDAR system 500 to when return light pulse 508 arrives back at LiDAR system 500 can be measured (e.g., by a processor or other electronics, such as control circuitry 350, within the LiDAR system). This time-of-flight combined with the knowledge of the speed of light can be used to determine the range / di stance from LiDAR system 500 to the portion of object 506 where light pulse 502 scattered or reflected.

[0112] By directing many light pulses, as depicted in FIG. 5B, LiDAR system 500 scans the external environment (e.g., by directing light pulses 502, 522, 526, 530 along light paths 504, 524, 528, 532, respectively). As depicted in FIG. 5C, LiDAR system 500 receives return light pulses 508, 542, 548 (which correspond to transmitted light pulses 502, 522, 530, respectively). Return light pulses 508, 542, and 548 are formed by scattering or reflecting the transmitted light pulses by one of objects 506 and 514. Return light pulses 508, 542, and 548 may return to LiDAR system 500 along light paths 510, 544, and 546, respectively. Based on the direction of the transmitted light pulses (as determined by LiDAR system 500) as well as the calculated range from LiDAR system 500 to the portion of objects that scatter or reflect the light pulses (e.g., the portions of objects 506 and 514), the external environment within the detectable range (e.g., the field of view between path 504 and 532, inclusively) can be precisely mapped or plotted (e.g., by generating a 3D point cloud or images).Attorney Docket Number: 11325.10209W001

[0113] If a corresponding light pulse is not received for a particular transmitted light pulse, then LiDAR system 500 may determine that there are no objects within a detectable range of LiDAR system 500 (e.g., an object is beyond the maximum scanning distance of LiDAR system 500). For example, in FIG. 5B, light pulse 526 may not have a corresponding return light pulse (as illustrated in FIG. 5C) because light pulse 526 may not produce a scattering event along its transmission path 528 within the predetermined detection range. LiDAR system 500, or an external system in communication with LiDAR system 500 (e.g., a cloud system or service), can interpret the lack of return light pulse as no object being disposed along light path 528 within the detectable range of LiDAR system 500.

[0114] In FIG. 5B, light pulses 502, 522, 526, and 530 can be transmitted in any order, serially, in parallel, or based on other timings with respect to each other. Additionally, while FIG. 5B depicts transmitted light pulses as being directed in one dimension or one plane (e.g., the plane of the paper), LiDAR system 500 can also direct transmitted light pulses along other dimension(s) or plane(s). For example, LiDAR system 500 can also direct transmitted light pulses in a dimension or plane that is perpendicular to the dimension or plane shown in FIG. 5B, thereby forming a 2-dimensional transmission of the light pulses. This 2-dimensional transmission of the light pulses can be point-by-point, line-by-line, all at once, or in some other manner. That is, LiDAR system 500 can be configured to perform a point scan, a line scan, a one-shot without scanning, or a combination thereof. A point cloud or image from a1-dimensional transmission of light pulses (e.g., a single horizontal line) can generate 2-dimensional data (e g., (1) data from the horizontal transmission direction and (2) the range or distance to objects). Similarly, a point cloud or image from a 2-dimensional transmission of light pulses can generate 3-dimensional data (e.g., (1) data from the horizontal transmission direction, (2) data from the vertical transmission direction, and (3) the range or distance to objects). In general, a LiDAR system performing an / / -dimensional transmission of light pulses generates ( / / + 1 ) dimensional data. This is because the LiDAR system can measure the depth of an object or the range / di stance to the object, which provides the extra dimension of data.Therefore, a 2D scanning by a LiDAR system can generate a 3D point cloud for mapping the external environment of the LiDAR system.

[0115] The density of a point cloud refers to the number of measurements (data points) per area performed by the LiDAR system. A point cloud density relates to the LiDAR scanningAttorney Docket Number: 11325.10209W001resolution. Typically, a larger point cloud density, and therefore a higher resolution, is desired at least for the region of interest (ROI). The density of points in a point cloud or image generated by a LiDAR system is equal to the number of pulses divided by the field of view. In some embodiments, the field of view can be fixed. Therefore, to increase the density of points generated by one set of transmission-receiving optics (or transceiver optics), the LiDAR system may need to generate a pulse more frequently. In other words, a light source in the LiDAR system may have a higher pulse repetition rate (PRR). On the other hand, by generating and transmitting pulses more frequently, the farthest distance that the LiDAR system can detect may be limited. For example, if a return signal from a distant object is received after the system transmits the next pulse, the return signals may be detected in a different order than the order in which the corresponding signals are transmitted, thereby causing ambiguity if the system cannot correctly correlate the return signals with the transmitted signals.

[0116] To illustrate, consider an example LiDAR system that can transmit laser pulses with a pulse repetition rate between 500 kHz and 1 MHz. Based on the time it takes for a pulse to return to the LiDAR system and to avoid mix-up of return pulses from consecutive pulses in a typical LiDAR design, the farthest distance the LiDAR system can detect may be 300 meters and 150 meters for 500 kHz and 1 MHz, respectively. The density of points of a LiDAR system with 500 kHz repetition rate is half of that with 1 MHz. Thus, this example demonstrates that, if the system cannot correctly correlate return signals that arrive out of order, increasing the repetition rate from 500 kHz to 1 MHz (and thus improving the density of points of the system) may reduce the detection range of the system. Various techniques are used to mitigate the tradeoff between higher PRR and limited detection range. For example, multiple wavelengths can be used for detecting objects in different ranges. Optical and / or signal processing techniques (e.g., pulse encoding techniques) are also used to correlate between transmitted and return light signals.

[0117] Various systems, apparatus, and methods described herein may be implemented using digital circuitry, or using one or more computers using well-known computer processors, memory units, storage devices, computer software, and other components. Typically, a computer includes a processor for executing instructions and one or more memories for storing instructions and data. A computer may also include, or be coupled to, one or more mass storage devices, such as one or more magnetic disks, internal hard disks and removable disks, magnetooptical disks, optical disks, etc.Attorney Docket Number: 11325.10209W001

[0118] Various systems, apparatus, and methods described herein may be implemented using computers operating in a client-server relationship. Typically, in such a system, the client computers are located remotely from the server computers and interact via a network. The client-server relationship may be defined and controlled by computer programs running on the respective client and server computers. Examples of client computers can include desktop computers, workstations, portable computers, cellular smartphones, tablets, or other types of computing devices.

[0119] Various systems, apparatus, and methods described herein may be implemented using a computer program product tangibly embodied in an information carrier, e.g., in a non-transitory machine-readable storage device, for execution by a programmable processor; and the method processes and steps described herein, including one or more of the steps of at least some of the FIGs. 1-10, may be implemented using one or more computer programs that are executable by such a processor. A computer program is a set of computer program instructions that can be used, directly or indirectly, in a computer to perform a certain activity or bring about a certain result. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0120] A high-level block diagram of an example apparatus that may be used to implement systems, apparatus and methods described herein is illustrated in FIG. 6. Apparatus 600 comprises a processor 610 operatively coupled to a persistent storage device 620 and a main memory device 630. Processor 610 controls the overall operation of apparatus 600 by executing computer program instructions that define such operations. The computer program instructions may be stored in persistent storage device 620, or other computer-readable medium, and loaded into main memory device 630 when execution of the computer program instructions is desired. For example, processor 610 may be used to implement one or more components and systems described herein, such as control circuitry 350 (shown in FIG. 3), vehicle perception and planning system 220 (shown in FIG. 2A), and vehicle control system 280 (shown in FIG. 2A). Thus, the method steps of at least some of FIGs. 1-10 can be defined by the computer program instructions stored in main memory device 630 and / or persistent storage device 620 and controlled by processor 610 executing the computer program instructions. For example, theAttorney Docket Number: 11325.10209W001computer program instructions can be implemented as computer executable code programmed by one skilled in the art to perform an algorithm defined by the method steps discussed herein in connection with at least some of FIGs. 1-10. Accordingly, by executing the computer program instructions, the processor 610 executes an algorithm defined by the method steps of these aforementioned figures. Apparatus 600 also includes one or more network interfaces 680 for communicating with other devices via a network. Apparatus 600 may also include one or more input / output devices 690 that enable user interaction with apparatus 600 (e.g., display, keyboard, mouse, speakers, buttons, etc.).

[0121] Processor 610 may include both general and special purpose microprocessors and may be the sole processor or one of multiple processors of apparatus 600. Processor 610 may comprise one or more central processing units (CPUs), and one or more graphics processing units (GPUs), which, for example, may work separately from and / or multi-task with one or more CPUs to accelerate processing, e.g., for various image processing applications described herein.Processor 610, persistent storage device 620, and / or main memory device 630 may include, be supplemented by, or incorporated in, one or more application-specific integrated circuits (ASICs) and / or one or more field programmable gate arrays (FPGAs).

[0122] Persistent storage device 620 and main memory device 630 each comprise a tangible non-transitory computer readable storage medium. Persistent storage device 620, and main memory device 630, may each include high-speed random access memory, such as dynamic random access memory (DRAM), static random access memory (SRAM), double data rate synchronous dynamic random access memory (DDR RAM), or other random access solid state memory devices, and may include non-volatile memory, such as one or more magnetic disk storage devices such as internal hard disks and removable disks, magneto-optical disk storage devices, optical disk storage devices, flash memory devices, semiconductor memory devices, such as erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), digital versatile disc read-only memory (DVD-ROM) disks, or other non-volatile solid state storage devices.

[0123] Input / output devices 690 may include peripherals, such as a printer, scanner, display screen, etc. For example, input / output devices 690 may include a display device such as aAttorney Docket Number: 11325.10209W001cathode ray tube (CRT), plasma or liquid crystal display (LCD) monitor for displaying information to a user, a keyboard, and a pointing device such as a mouse or a trackball by which the user can provide input to apparatus 600.

[0124] Any or all of the functions of the systems and apparatuses discussed herein may be performed by processor 610, and / or incorporated in, an apparatus or a system such as LiDAR system 300. Further, LiDAR system 300 and / or apparatus 600 may utilize one or more neural networks or other deep-learning techniques performed by processor 610 or other systems or apparatuses discussed herein.

[0125] One skilled in the art will recognize that an implementation of an actual computer or computer system may have other structures and may contain other components as well, and that FIG. 6 is a high-level representation of some of the components of such a computer for illustrative purposes.

[0126] As described above, a current LiDAR system often includes transmitter optics and receiver optics designed with typical optical lenses and lens groups. Complex lens groups with multiple glass-based optical elements are often used to collimate laser light to form collimated transmission light beams, and to collect and focus return light onto detectors, making the system bulky and expensive.

[0127] FIG. 7 illustrates an example of a typical LiDAR light receiver 700 designed with, for example, glass-based optical lens or lens groups. When transmission light beams are scattered or reflected by one or more objects, a portion of the scattered or reflected light forms return light that returns to the LiDAR system. The LiDAR light receiver 700 is configured to collect and focus the return light 720. As shown in FIG. 7, due to a large number of the transmission light beams, the return light 720 also includes many groups of return light corresponding to the large number of transmission light beams. As shown in FIG. 7, the LiDAR light receiver 700 includes a LiDAR detector 712. The LiDAR detector 712 normally includes multiple light detectors arranged in a detector array (e.g., ID or 2D detector array), to detect the many groups of return light in parallel and enable the LiDAR system to generate good quality point cloud. In order to focus the return light 720 on the corresponding light detectors in the LiDAR detector 712, multiple glass-based optical lenses are used. As shown in FIG. 7, in one example, the LiDAR light receiver 700 includes a convex lens 702, a concave lens 704, a convex lens 706, a concaveAttorney Docket Number: 11325.10209W001lens 708, and a filter 710. At least some of these optical elements are glass-based. As a result, these optical elements occupy a large space, making the LiDAR light receiver 700 quite bulky.

[0128] Further, to collect more return light from a large FOV, a large front-end optical aperture is required. As shown in FIG. 7, the convex lens 702 is a large size optical lens at the front end of the LiDAR light receiver 700. The large front-end optical aperture also affects other lenses positioned downstream to the convex lens 702. For example, as shown in FIG. 7, the concave lens 704 and the convex lens 706 may also be large size lenses, to match the large front-end optical aperture of the convex lens 702. Therefore, the overall size of the LiDAR light receiver 700 is also large. The combination of multiple and large-size lenses further increases manufacturing costs and difficulties in assembly. For example, a large and complex lens housing with mechanical structures to hold these multiple optical elements align is also required, thereby making the LiDAR system even more bulky and expensive. Therefore, there is a need for techniques to optimize the LiDAR light receiver to use fewer, reduced size, and lower cost optical components.

[0129] A Metalens is an advanced type of lens that uses metamaterials to manipulate and control light in specific ways. Different from typical optical lenses, Metalenses are thin and include subwavelength structures at the nanoscale, which can interact with light in ways that typical glass-based optical lenses can or cannot. Metalenses and their applications in LiDAR systems are described in more detail in U.S. non-provisional patent application No. 18 / 373,252, filed on September 26, 2023, entitled “COMPACT LIDAR SYSTEM WITH METALENSES”, the content of which is incorporated by reference in it is entirety for all purposes.

[0130] Moreover, Metalenses are capable of being mass produced using well-developed wafer manufacturing processes. FIG. 8 is a diagram illustrating an example of Metalenses formed on a wafer 800 in accordance with various embodiments. As shown in FIG. 8, the wafer 800 can include a thin, flat slice or a disk of semiconductor and / or dielectric material. The wafer 800 can be a semiconductor wafer or a dielectric wafer Dielectric wafer refers to a wafer having a substrate with dielectric material. A semiconductor wafer can be, for example, a silicon-based wafer, a gallium arsenide (GaAs) based wafer, a silicon carbide (SiC) based wafer, a gallium nitride (GaN) based wafer, an indium phosphide (InP) based wafer, or a wafer based on any other semiconductor materials. A dielectric wafer can include, for example, a substrateAttorney Docket Number: 11325.10209W001containing silicon dioxide (SiCh), a substrate containing silicon nitride (SisN^, a substrate containing aluminum oxide (AI2O3), or a substrate containing any other dielectric materials. The wafer 800 can be any size (e.g., 300 mm or 12 inches) in diameter. The wafer 800 can be flat and thin (e.g., having a thickness in the order of micrometers or millimeters).

[0131] The wafer 800 can have a single or multiple flat surfaces on which subwavelength structures are formed. The subwavelength structures refer to patterns or features that are smaller in size than the wavelength of the light or electromagnetic wave they interact with. For example, the dimensions of these subwavelength structures are on the nanoscale level (e.g., nanoslits, nanorods, nanodisks, etc.), typically much smaller than the wavelengths of the light (e.g., visible light or infrared light). When light encounters an object or a structure that is much larger than its wavelength, it behaves in a manner predicted by the laws of classical optics. However, when light interacts with structures on the order of its wavelength or smaller, it can exhibit different behaviors due to diffraction, interference, and other wave phenomena. For example, the subwavelength structures are configured such that the phase, amplitude, and polarization of incident light can be controlled in a desired manner to achieve specific optical effects. These effects can include bending, focusing, collimating, transmitting, filtering, beam homogenizing, and manipulating light in ways that may or may not be possible with typical optical lenses and macroscopic structures.

[0132] As shown in FIG. 8, the subwavelength structures can form 2-dimensional (2D) or 3-dimensional (3D) patterns in the wafer 800. As shown in FIG. 8, the pattern for a Metalens 802 on the wafer 800 can be of a rectangular shape or a square shape. It is understood that pattern for a Metalens can also have any other desired shape. The wafer 800 (e.g., a 12-inch wafer) is usually cut into a large number of small Metalenses using a wafer dicing process. In a mass production, the cost of fabricating a wafer for Metalenses is often fixed or roughly fixed, so the cost of each Metalens is inversely proportional to the number of Metalenses that can be obtained from the wafer. For example, the cost of a Metalens with a size larger than 20 mm can be significant. Therefore, it is cost-effective to have each Metalens 802 in a small size. Further, by using the wafer dicing process, unlike most typical lenses with a circular cross section, it may be cost-effective to keep the Metalens 802 of rectangular or square shape.

[0133] FIGs. 9A-9D are diagrams illustrating examples of LiDAR light receivers having a Metalens or Metalens group in accordance with various embodiments. FIG. 9A is a diagramAttorney Docket Number: 11325.10209W001illustrating an example of a LiDAR light receiver 900 including a Metalens 904 in accordance with various embodiments. In some embodiments, a Metalens group can also be used in LiDAR light receiver 900 to implement the Metalens 904 shown in FIG. 9A.

[0134] The LiDAR light receiver 900 can be used to implement optical receiver and light detector 330 shown in FIG. 3. As shown in FIG. 9 A, the LiDAR light receiver 900 includes a lens 902, a Metalens 904, and a detector array 906. In some embodiments, a lens group can also be used in the LiDAR light receiver 900 to implement the lens 902 shown in FIG. 9A. The lens (or the lens group) 902 used in this disclosure refers to typical glass-based or other transparent material-based lens (or lens group) having curvature on the surface(s). Compared with the typical LiDAR light receiver 700 described above, multiple glass-based optical lenses (e.g., lenses 702, 704, 706, and 708 shown in FIG. 7) can be replaced with one glass-based lens 902 and one Metalens 904, or a Metalens group, thereby greatly reducing the bulkiness of a LiDAR system.

[0135] FIG. 9A illustrates a 3D view of the LiDAR light receiver 900. As described above, when transmission light beams are scattered or reflected by one or more objects, a portion of the scattered or reflected light forms return light that returns to the LiDAR system. The LiDAR light receiver 900 is configured to receive the return light 920. As shown in FIG. 9A, the return light 920 includes multiple groups of return light 920A-E corresponding to the transmission light beams with different angles in the vertical FOV or vertical direction (also referred to as the vertical angles). While FIG. 9A illustrates five different groups of return light 920A-E for the return light 920, it is understood that the return light 920 can include more or fewer groups of return light, depending on the number of transmission light beams. In some embodiments, when the transmission light beams are collimated by using a collimation lens or lens group, the return light 920 formed based on the collimated transmission light beams is also collimated. As shown in FIG. 9A, each of the multiple groups of return light 920A-E includes multiple parallel light rays.

[0136] As shown in FIG. 9A, the lens 902 is configured to receive the multiple groups of return light 920A-E from the one or more objects (not shown in FIG. 9A) in a field-of-view. Due to the large receiving aperture required in a LiDAR light receiver, the lens 902 can be relatively large (e.g., a diameter of 20-25 mm or more) to collect as much return light 920 as possible. In some embodiments, the lens 902 or lens group includes spherical lenses. As shown in FIG. 9A, theAttorney Docket Number: 11325.10209W001lens 902 is a spherical lens. Spherical lenses are relatively low-cost lenses, and it is cost-effective to use spherical lenses (e.g., the lens 902) with large sizes at the front of a LiDAR light receiver (e.g., LiDAR light receiver 900).

[0137] As shown in FIG. 9A, the lens 902 further focuses and directs the multiple groups of return light 920A-E toward the Metalens 904, such that portions of the multiple groups of return light 920A-E overlaps on the Metalens 904. As shown in FIG. 9A, after passing through the lens 902, the multiple groups of return light 920A-E converge. As such, the area required for the multiple groups of return light 920A-E to pass through Metalens 904 is smaller than that of the lens 902. In one example, portions of the multiple groups of return light 920A-E may overlap on the Metalens 904. For example, as shown in FIG. 9A, groups of return light 920A partially overlaps with groups of return light 920B. Groups of return light 920B partially overlaps with groups of return light 920A and groups of return light 920C. Groups of return light 920C partially overlaps with groups of return light 920B and groups of return light 920D. Groups of return light 920D partially overlaps with groups of return light 920C and groups of return light 920E.

[0138] Further, as described above, the multiple groups of return light 920 A-E are formed based on the transmission light beams and correspond to the transmission light beams with different angles in the vertical FOV or vertical direction (also referred to as the vertical angles). Therefore, the multiple groups of return light 920A-E also have different vertical angles. In turn, after passing through the lens 902, the multiple groups of return light 920A-E with different vertical angles converge to an approximately rectangular region on Metalens 904. The region is also referred to as the convergence region on the Metalens 904. As shown in FIG. 9A, such a convergence region (e.g., the area on the Metalens 904 for the multiple groups of return light 920A-E to pass through) can be narrower in its horizontal direction, and elongated in the vertical direction. As used in this disclosure, the horizontal or vertical direction of the Metalens corresponds to the horizontal or vertical direction of the FOV scanned or covered by the transmission light beams of the LiDAR system. Typically, the vertical direction of the FOV (also referred to as the vertical FOV) is the direction perpendicular to the road surface of a vehicle to which the LiDAR system is mounted.

[0139] As shown in FIG. 9A, the Metalens 904 is configured to further focus and direct the multiple groups of return light 920A-E to the detector array 906. For example, as describedAttorney Docket Number: 11325.10209W001above, the nanostructures of the Metalens 904 can be customized to focus and converge the groups of return light 920A-E to a respective detector of detector array 906. In one example, as shown in FIG. 9A, the multiple groups of return light 920A-E are received by the detector array 906 within a rectangular convergence region 910 on the detector array 906. As shown in FIG.9A, different from the typical optical lenses (e.g., glass-based lenses 702, 704, 706 and 708 shown in FIG. 7, or lens 902 shown in FIG. 9) with circular cross sections, the Metalens 904 or Metalens group can have a rectangular or square shape.

[0140] As shown in FIG. 9A, the multiple groups of return light 920A-E converge and are received by the detector array 906 within a rectangular convergence region 910. As described above, the multiple groups of return light 920A-E have different vertical angles. Therefore, the rectangular convergence region 910 on the detector array 906 is elongated in vertical direction and narrower in horizontal direction. As shown in FIG. 9A, the shape and / or size of the rectangular convergence region 910 matches those of the detector array 906 (e.g., also having a rectangular shape). In some embodiments, the detector array 906 is elongated in one direction and narrower in another direction, forming a substantially rectangular shape. As shown in the example of FIG. 9A, the detector array 906 is also elongated in vertical direction and narrower in horizontal direction. The longer edge of the Metalens 904 can be substantially parallel to the longer edge of the detector array 906. Similarly, the shorter edge of Metalens 904 can be parallel to the shorter edge of the detector array 906. It is understood, however, that the shapes of the detector array 906 and Metalens 904 do not necessarily need to correspond to each other, as long as the detectors of detector array 906 are positioned to receive the respective group of return light 920A-E.

[0141] FIG. 9B is a diagram illustrating an example of a detector array 906 used in the LiDAR light receiver 900 in accordance with various embodiments. As shown in FIG. 9B, the detector array 906 includes multiple light detectors 916A-E (collectively as 916). While FIG. 9B illustrates five light detectors 916A-E in the detector array 906, it is understood that the detector array 906 can include more or fewer light detectors 916. The number of the light detectors 916A-E shown in FIG. 9B corresponds to the number of groups of return light 920 A-E shown in FIG. 9 A. Each of the light detectors 916A-E is configured to detect a corresponding one of the multiple groups of return light 920A-E, such that the multiple groups of return light 920A-E withAttorney Docket Number: 11325.10209W001different vertical angles can be detected in parallel. This enables the LiDAR system to generate better quality point cloud and to improve the detection efficiency and throughput.

[0142] As shown in FIG. 9B, the multiple light detectors 916A-E are arranged in a substantial one-dimensional (ID) array and positioned in parallel to the long edge of the Metalens 904. Therefore, the detector array 906 is elongated in one direction and narrower in another direction, forming a substantially rectangular shape. As shown in FIG. 9B, the short edges of the detectors 916A-E of detector array 906 align with the horizontal direction, and the long edges of the detectors 916A-E of detector array 906 align with the vertical direction. This corresponds to the Metalens 904 with a smaller size in the horizontal direction than that in the vertical direction. As described above, the long edge of the Metalens 904 is substantially parallel to the long edge of the detector array 906. As a result, the shape and / or size of rectangular convergence region 910 can match with those of the detector array 906, so that the multiple groups of return light 920A-E can be detected in parallel. Therefore, by customizing the Metalens 904 in the LiDAR light receiver 900, the multiple groups of return light 920A-E can be precisely focused onto the corresponding light detectors 916A-E, without degrading LiDAR detection performance.

[0143] Referring back to FIG. 9A, the Metalens 904 includes a planar surface. As described above, a Metalens can be thin and flat, and includes subwavelength structures at the nanoscale. It is understood that Metalens may include a planar surface which is flat when viewed at the macroscopic level (e.g., with naked eyes) but may have nanostructures when viewed at the microscopic level (e g., with an electron microscope). The subwavelength structures are configured to manipulate phase or amplitude of incident light. In some embodiments, the Metalens 904 is formed on a semiconductor wafer or a dielectric wafer (e.g., the wafer 800 shown in FIG. 8). The semiconductor or dielectric wafer can have single or multiple flat surfaces on which subwavelength structures are formed to manipulate incident light.

[0144] Due to the Metalens 904 having subwavelength structures to manipulate incident light, the Metalens 904 can compensate the optical aberration and distortion that usually requires multiple glass-based lenses. As a result, the Metalens 904 can replace multiple glass-based lenses used in typical LiDAR light receivers. For example, compared with the typical LiDAR light receiver 700 described above, one Metalens 904 replaces all three glass-based lenses 704, 706, and 708, thereby greatly reducing the overall size of a LiDAR light receiver and manufacturing costs on multiple lenses. Further, due to the thin-and-flat nature of the MetalensAttorney Docket Number: 11325.10209W001904, the lenses mounting and assembly also becomes easier, thereby reducing costs on the mechanical housings.

[0145] As described above, by using the wafer dicing process, it is cost-effective to have a Metalens in a small size and of rectangular or square shape. As shown in the example of FIG.9A, the Metalens 904 can of rectangular shape. As described above, the detector array 906 is positioned such that its short edges align with the horizontal direction. This matches the Metalens 904 with its short edges aligned with the horizontal direction. Further, the Metalens 904 is positioned closer to the detector array 906 than to the lens 902. As shown in FIG. 9A, after passing through the lens 902, the multiple groups of return light 920A-E converge. The furtherer away from the lens 902, the smaller beam size the multiple groups of return light 920 A-E becomes. Therefore, by positioning the Metalens 904 closer to the detector array 906 than to the lens 902, the Metalens 904 can have a smaller size and still provide enough surface area for the multiple groups of return light 920A-E to pass through. Although the lens 902 is in a relatively large size (e.g., a diameter of 20-25 mm or more), the size of the Metalens 904 can be small (e.g., 8 x 16 mm or less). Thus, replacing typical glass-based lenses with Metalens 904 and / or placing the Metalens 904 at a desired location can reduce the overall size of the LiDAR light receiver 900 and the mechanical housing. Also, Metalens 904 in a small size reduces its manufacturing cost (e.g., a single wafer can provide more Metalens, which reduces the cost of each Metalens), enabling more compact and cost-effective LiDAR systems.

[0146] FIGs. 9C and 9D are diagrams illustrating another example of a LiDAR light receiver 930 including a Metalens 904 in accordance with various embodiments. In some embodiments, a Metalens group can also be used in LiDAR light receiver 930 to implement the Metalens 904 shown in FIGs. 9C and 9D. FIG. 9C is a side view of the LiDAR light receiver 930. FIG. 9D is a top view of the LiDAR light receiver 930.

[0147] The LiDAR light receiver 930 can also be used to implement optical receiver and light detector 330 shown in FIG. 3. Similar to the LiDAR light receiver 900, the LiDAR light receiver 930 also includes a lens 902, a Metalens 904, and a detector array 906. The details of these components are thus not repeatedly described. In some embodiments, a lens group can also be used in LiDAR light receiver 930 to implement the lens 902 shown in FIGs. 9C and 9D.

[0148] The LiDAR light receiver 930 is also configured to receive return light 920. Similar to FIG. 9A, the return light 920 includes multiple groups of return light 920A-E shown in FIGs. 9CAttorney Docket Number: 11325.10209W001and 9D. As described above, the multiple groups of return light 920A-E are formed based on the transmission light beams and correspond to the transmission light beams with different vertical angles. As a result, the multiple groups of return light 920A-E also have different vertical angles. As shown in FIG. 9C, in the side view, the multiple groups of return light 920A-E are distinguished in the vertical direction. As shown in FIG. 9D, in the top view, the multiple groups of return light 920A-E overlap in the horizontal direction.

[0149] As shown in FIGs, 9C and 9D, the LiDAR light receiver 930 further includes a bandpass fdter 914 optically coupled to the Metalens 904. The bandpass fdter 914 operates to filter out light having undesired wavelengths (e.g., sunlight or any other undesired light interference), thereby reducing optical noise and background light. In some embodiments, bandpass filter 914 can be configured to have a narrow passband. For example, the passband of the filter 914 can be configured to be centered at the wavelength of the return light 920, with a bandwidth of 10-20 nm. As shown in FIGs. 9C and 9D, the bandpass filter 914 can have a substantially similar size and shape compared to those of the Metalens 904. The bandpass filter 914 can placed together with the Metalens 904 (e.g., near Metalens 904) or even integrated with Metalens 904 (e.g., manufactured on the same wafer). In some embodiments as shown in FIGs. 9C and 9D, the bandpass filter is placed upstream to the Metalens 904. In other embodiments, the bandpass filter can be placed downstream to the Metalens 904.

[0150] As shown in FIG. 9C, the lens 902 has an optical aperture 912. As shown in FIG. 9C, the optical aperture 912 has a diameter of at least 20 millimeters. As a result, the lens 902 has a large size configured to collect as much return light 920 as possible to meet the detection range requirement.

[0151] As described above, the lens 902 can be relatively large to collect as much return light as possible, while the Metalens 904 can be configured in a size much smaller than the lens 902. As shown in FIG. 9C, the size of the Metalens is smaller than the optical aperture 912. The long edge of the Metalens 904 is less than or equal to 16 millimeters. As shown in FIG. 9D, the short edge of the Metalens 904 is less than or equal to 8 millimeters.

[0152] As described above, the long edge of the Metalens 904 is substantially parallel to a long edge of the detector array 906. As described above, the detector array 906 is positioned with its short edges in horizontal direction, corresponding to the short edges of the Metalens 904 in the horizontal direction.Attorney Docket Number: 11325.10209W001

[0153] FIGs. 10A and 10B are diagrams illustrating an example of using a multi-focus Metalens or Metalens group to improve LiDAR system performance in accordance with various embodiments. FIG. 10A illustrates a LiDAR light receiver 1000 including typical glass-based optical lenses and a detector array 906. As shown in FIG. 10A, the glass-based optical lenses can include a lens 902 and a lens 1008. In some embodiments, a lens group can also be used in LiDAR light receiver 1000 to implement the lens 902 shown in FIG. 10A. The lens 1008 also refers to glass-based or other transparent material -based lens having curvature on the surface(s). Normally, a glass-based (or other transparent material-based) optical lens is oftentimes monofocal, because manufacturing a glass-based (or other transparent material -based) optical lens with multi-focus (e.g., aspheric lens) is very difficult and costly. Therefore, both the lens 902 and the lens 1008 are mono-focal lenses.

[0154] As described above, when transmission light beams are scattered or reflected by one or more objects in a FOV, a portion of the scattered or reflected light forms return light that returns to the LiDAR system. The LiDAR light receiver 1000 is configured to receive return light from the one or more objects. Normally, a typical LiDAR light receiver is designed to receive return light from far objects. As shown in FIG. 10A, a group of parallel rays illustrate a first group of return light 1020A from the one or more far objects (not shown in FIG. 10A). For example, the one or more far objects are located at distances of greater than 5 meters from the LiDAR light receiver 1000.

[0155] When there are also one or more near objects (e.g., near object 1022) in the FOV, a second group of return light 1020B from the one or more near objects can also enter the LiDAR light receiver 1000. For example, the one or more near objects are located within distances of less than one meter from the LiDAR light receiver 1000. As shown in FIG. 10A, because the optical lenses (e.g., the lens 902 and the lens 1008) are mono-focal and aligned for far objects, the first group of return light 1020 A from the one or more far objects can focus correctly on the detector array 906 of the LiDAR light receiver 1000. However, the second group of return light 1020B from near-distance objects is defocused on the detector array 906. In turn, the defocused return light (e.g., the second group of return light 1020B) can form large and blurry spots on the plane of the detector array 906, overfilling the photosensitive areas of light detectors in the detector array 906. As a result, less light may be detected by the one or more light detectors, thereby degrading detection performance of the LiDAR system.Attorney Docket Number: 11325.10209W001

[0156] To address this issue, FIG. 10B illustrates a LiDAR light receiver 1010 having a multifocal Metalens 1004 in accordance with various embodiments. In some embodiments, a Metalens group can also be used in LiDAR light receiver 1010 to implement the Metalens 1004 shown in FIG. 10B. As described above, Metalenses include subwavelength structures configured to manipulate incident light. Therefore, a Metalens or Metalens group can be customized to have different subwavelength structures at different regions to achieve a multifocus effect. As shown in FIG. 10B, the Metalens 1004 includes at least an inner region 1042 having a first focusing power, and an outer region 1044 having a second focusing power. The second focusing power is greater than the first focusing power. The focusing power refers to the ability of an optical element (e.g., a lens) to focus light. Quantitatively, the focusing power is equal to the reciprocal of the focal length of the optical element. Therefore, the first focusing power is lower and corresponds to a longer focal length. The second focusing power is greater and corresponds to a shorter focal length.

[0157] As shown in FIG. 10B, the LiDAR light receiver 1010 further includes a lens 902 and a detector array 906. In some embodiments, a lens group can also be used in LiDAR light receiver 1010 to implement the lens 902 shown in FIG. 10B. The LiDAR light receiver 1010 is configured to receive return light. Similar to FIG .10A, the return light includes a first group of return light 1020A from one or more far objects (not shown in FIG. 10B), and a second group of return light 1020B from one or more near objects (e.g., near object 1022 shown in FIG. 10B). The one or more far objects are located further from the LiDAR light receiver 1010 than the one or more near objects. Both the one or more far objects and the one or more near objects are in the FOV. In some embodiments, the one or more far objects are located at distances greater than 5 meters from the LiDAR light receiver 1010. In some embodiments, the one or more near objects are located within distances of less than one meter from the LiDAR light receiver 1010.

[0158] As shown in FIG. 10B, the lens 902 is configured to focus and direct the return light 1020A and 1020B toward the Metalens 1004, such that the first group of return light 1020 A passes through the inner region 1042 of the Metalens 1004, and the second group of return light 1020B passes through the outer region 1044 of the Metalens 1004. As shown in FIG. 10B, the Metalens 1004 is configured to focus the first group of return light 1020 A with the first focusing power, and focus the second group of return light 1020B with the second focusing power. As described above, the first focusing power is lower and corresponds to a longer focal length. TheAttorney Docket Number: 11325.10209W001second focusing power is greater and corresponds to a shorter focal length. As a result, both the first group of return light 1020A from the one or more far objects and the second group of return light 1020B from the one or more near objects substantially converge to their respective focal points on the detector array 906. The detector array 906 is configured to detect both the focused first group of return light 1020 A and the focused second group of return light 1020B. Therefore, with the multi-focal Metalens 1004 in the LiDAR light receiver 1010, both far objects and near objects can be focused on detector arrays 906, thereby improving detection performance of the LiDAR system.

[0159] The foregoing specification is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the specification, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that various modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention.

Claims

Attorney Docket Number: 11325.10209W001CLAIMSWHAT IS CLAIMED IS:

1. A LiDAR light receiver comprising:a lens or lens group,a Metalens or Metalens group, anda detector array,wherein the lens or lens group is configured to:receive a plurality of groups of return light from one or more objects in a field-of-view, andfocus and direct the plurality of return light beams toward the Metalens or Metalens group such that portions of the plurality of groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region,wherein the Metalens or the Metalens group is configured to:focus and direct the plurality of groups of return light to the detector array such that the plurality of groups of return light are received by the detector array within a convergence region.

2. The LiDAR light receiver of claim 1, wherein the lens or lens group comprises spherical lenses.

3. The LiDAR light receiver of claim 1, wherein an optical aperture of the lens or lens group has a diameter of at least 20 millimeters.

4. The LiDAR light receiver of claim 3, wherein a size of the Metalens or Metalens group is smaller than the optical aperture of the lens or lens group.

5. The LiDAR light receiver of claim 1, wherein the Metalens or Metalens group is of rectangular or square shape.

6. The LiDAR light receiver of claim 5, wherein a long edge of the Metalens or Metalens group is less than or equal to 16 millimeters.Attorney Docket Number: 11325.10209W0017. The LiDAR light receiver of claim 5, wherein a short edge of the Metalens or Metalens group is less than or equal to 8 millimeters.

8. The LiDAR light receiver of claim 1, wherein the detector array is elongated in one direction and narrower in another direction, forming a substantially rectangular shape.

9. The LiDAR light receiver of claim 8, wherein a long edge of the Metalens or Metalens group is substantially parallel to a long edge of the detector array.

10. The LiDAR light receiver of claim 1, wherein the detector array comprises a plurality of light detectors arranged in a substantially one-dimensional array and positioned in parallel to a long edge of the Metalens or Metalens group.

11. The LiDAR light receiver of claim 1, wherein the Metalens or Metalens group is positioned closer to the detector array than to the lens or lens group.

12. The LiDAR light receiver of claim 1, wherein the Metalens or Metalens group is placed together with a bandpass filter of substantially similar size and shape.

13. The LiDAR light receiver of claim 1, wherein the Metalens or Metalens group comprises a planar surface with nanoscale structures configured to manipulate phase or amplitude of incident light.

14. The LiDAR light receiver of claim 1, wherein the Metalens or Metalens group is formed on a semiconductor or dielectric wafer, the semiconductor or dielectric wafer comprising a substrate on which nanoscale structures are formed to manipulate incident light.

15. A LiDAR light receiver comprising:a lens or lens group,Attorney Docket Number: 11325.10209W001a Metalens or Metalens group comprising at least an inner region having a first focusing power and an outer region having a second focusing power greater than the first focusing power, a detector array,wherein the lens or lens group is configured to:receive return light comprising at least a first group of return light from one or more far objects in a field-of-view and a second group of return light from one or more near objects in the field-of-view, the one or more far objects being located further from the LiDAR light receiver than the one or more near objects, andfocus and direct the return light toward the Metalens or Metalens group such that the first group of return light passes through the inner region of the Metalens or Metalens group and the second group of return light passes through the outer region of the Metalens or Metalens group, wherein the Metalens or the Metalens group is configured to:focus the first group of return light with the first focusing power, and focus the second group of return light with the second focusing power, such that both the first group of return light and the second group of return light substantially converge to their respective focal points on the detector array, andwherein the detector array is configured to:detect the focused first group of return light and the focused second group of return light.

16. The LiDAR light receiver of claim 15, wherein the one or more far objects are located at distances of greater than 5 meters from the LiDAR light receiver.

17. The LiDAR light receiver of claim 15, wherein the one or more near objects are located within distances of less than one meter from the LiDAR light receiver.

18. A system for light ranging and detection (LiDAR), comprising:a LiDAR light receiver, the LiDAR light receiver comprising:a lens or lens group,a Metalens or Metalens group, anda detector array,wherein the lens or lens group is configured to:Attorney Docket Number: 11325.10209W001receive a plurality of groups of return light from one or more objects in a field-of-view, andfocus and direct the plurality of return light beams toward the Metalens or Metalens group such that portions of the plurality of groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region,wherein the Metalens or the Metalens group is configured to:focus and direct the plurality of groups of return light to the detector array such that the plurality of groups of return light are received by the detector array within a convergence region;a light source;a scanner; anda controller.

19. A system for light ranging and detection (LiDAR), comprising:a LiDAR light receiver, the LiDAR light receiver comprising:a lens or lens group,a Metalens or Metalens group comprising at least an inner region having a first focusing power and an outer region having a second focusing power greater than the first focusing power,a detector array,wherein the lens or lens group is configured to:receive return light comprising at least a first group of return light from one or more far objects in a field-of-view and a second group of return light from one or more near objects in the field-of-view, the one or more far objects being located further from the LiDAR light receiver than the one or more near objects, andfocus and direct the return light toward the Metalens or Metalens group such that the first group of return light passes through the inner region of the Metalens or Metalens group and the second group of return light passes through the outer region of the Metalens or Metalens group,wherein the Metalens or the Metalens group is configured to:Attorney Docket Number: 11325.10209W001focus the first group of return light with the first focusing power, and focus the second group of return light with the second focusing power, such that both the first group of return light and the second group of return light substantially converge to their respective focal points on the detector array, andwherein the detector array is configured to:detect the focused first group of return light and the focused second group of return light;a light source;a scanner; anda controller.

20. A vehicle comprising a system for light ranging and detection (LiDAR), the system comprising:a LiDAR light receiver, the LiDAR light receiver comprising:a lens or lens group,a Metalens or Metalens group, anda detector array,wherein the lens or lens group is configured to:receive a plurality of groups of return light from one or more objects in a field-of-view, andfocus and direct the plurality of return light beams toward the Metalens or Metalens group such that portions of the plurality of groups of return light overlap on the Metalens or Metalens group and converge to an approximately rectangular region,wherein the Metalens or the Metalens group is configured to:focus and direct the plurality of groups of return light to the detector array such that the plurality of groups of return light are received by the detector array within a convergence region;a light source;a scanner; anda controller.Attorney Docket Number: 11325.10209W00121. A vehicle comprising a system for light ranging and detection (LiDAR), the system comprising:a LiDAR light receiver, the LiDAR light receiver comprising:a lens or lens group,a Metalens or Metalens group comprising at least an inner region having a first focusing power and an outer region having a second focusing power greater than the first focusing power,a detector array,wherein the lens or lens group is configured to:receive return light comprising at least a first group of return light from one or more far objects in a field-of-view and a second group of return light from one or more near objects in the field-of-view, the one or more far objects being located further from the LiDAR light receiver than the one or more near objects, andfocus and direct the return light toward the Metalens or Metalens group such that the first group of return light passes through the inner region of the Metalens or Metalens group and the second group of return light passes through the outer region of the Metalens or Metalens group,wherein the Metalens or the Metalens group is configured to:focus the first group of return light with the first focusing power, and focus the second group of return light with the second focusing power, such that both the first group of return light and the second group of return light substantially converge to their respective focal points on the detector array, andwherein the detector array is configured to:detect the focused first group of return light and the focused second group of return light;a light source;a scanner; anda controller.

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