Light detection and ranging (LIDAR) system including modular components

Abstract

A modular LIDAR sensor system includes: a seed laser configured to output a beam; a modular modulator coupled to receive the beam output from the seed laser and modulate the beam to generate a modulated beam; a modular amplifier coupled to receive the modulated beam from the modular modulator and generate an amplified beam; and a modular transceiver chip coupled to the modular modulator and the modular amplifier, the transceiver chip being configured to emit a beam perpendicularly from a first surface of the transceiver chip through an optical window; and to receive a reflected beam from a target through the optical window.

Description

Technical Field

[0001] This disclosure generally relates to modular components for optical detection and ranging (LIDAR) systems, and more specifically to LIDAR systems including modular modulators, modular amplifiers, and modular transceiver chips. Background Technology

[0002] LiDAR sensor systems are used in a wide range of applications, from altimetry to imaging to collision avoidance. The design and implementation of LiDAR sensor systems can utilize photonic integrated circuits (PICs) or integrated optical circuits, which are chips containing photonic components. Past attempts have aimed to incorporate an increasing number of photonic components of LiDAR systems onto a single PIC. However, the problem with these attempts is that they are complex and significantly reduce yield when manufacturing such complex chips. Other existing methods have used fiber optic connectors to couple the different components of the LiDAR system. Besides the required additional space, the problem with using fiber optic cable connectors is the configuration complexity and alignment issues associated with using fiber optics and connectors. Therefore, a method is needed to construct LiDAR systems with high yield and reduced complexity. Summary of the Invention

[0003] Embodiments of this disclosure relate to a modular architecture for a light detection and ranging (LIDAR) sensor system for a vehicle, and more specifically to a LIDAR sensor system including modular components and a method for configuring components for collaboration and communication. According to one aspect of the subject matter described in this disclosure, a LIDAR sensor system is included, comprising: a seed laser configured to output a light beam; a modular modulator configured to receive the light beam output from the seed laser and modulate the light beam to generate a modulated light beam; a modular amplifier configured to receive the modulated light beam from the modular modulator and generate an amplified light beam, the modular amplifier including a specific semiconductor optical amplifier having multiple apertures; and a modular transceiver chip coupled to the modular modulator and the modular amplifier, the transceiver chip being configured to emit a light beam perpendicularly from a first surface of the transceiver chip through an optical window and receive a reflected light beam from a target through the optical window.

[0004] These and other implementations may each optionally include one or more of the following features. For example, a feature may include a seed laser comprising a laser having a grating structure providing optical feedback to output a beam, or a lens having a spacing in the range of 450 to 550 micrometers to couple the beam to a modular modulator. For example, a feature may also include the modular modulator performing in-phase and quadrature modulation or frequency modulation to generate a modulated beam. In another example, a feature may include the modular modulator and seed laser being integrated into a single chip to form a seed laser assembly. In another feature, the seed laser assembly is mounted on a first submount, and a modular transceiver chip coupled to the modular modulator is mounted on a second submount for aligning the height of the seed laser assembly and the height of the modular transceiver chip for optical coupling. In some features, the modular amplifier includes a semiconductor optical amplifier or a tapered semiconductor optical amplifier configured to receive the modulated beam from the modular modulator and generate an amplified beam through stimulated emission. For example, in one aspect, the modular amplifier includes one of indium phosphide (InP), gallium arsenide (GaAs), silicon nitride (SiN), mono-indium arsenide (InAs), gallium nitride (GaN), or indium antimonide (InSb). Features may also include a specific semiconductor optical amplifier having additional material on its sides for bow management. Furthermore, features may include: the modular amplifier including a first strip mounted on a first portion of the modular amplifier and a second strip mounted on a second portion of the modular amplifier, the second strip having a coefficient of thermal expansion matching that of the first strip; the first and second strips being configured to reduce the junction temperature of the modular amplifier; or further, the first and second strips being 16-aperture strips, and the modular amplifier including 16 tapered semiconductor optical amplifiers. For example, features may include a modular modulator optically coupled to the modular amplifier via a lens array, or a lens array compensating for the height difference between a first height of the modular modulator's pedestal and a second height of the modular amplifier's pedestal. Features may also include that the modular modulator, modular amplifier, and modular transceiver chips are fully tested before achieving high-volume integration. Other features may include beam splitters coupling the modular modulator to the modular amplifier, and the beam splitters comprising 1 to 16 beam splitters having a spacing in the range of 450 to 550 micrometers. For example, features may include a lens array coupling the modular modulator to the modular amplifier, and a beam splitter comprising a plurality of 1 to 4 beam splitter chips having a spacing in the range of 450 to 550 micrometers, wherein the lens array comprises four lenses and has a spacing in the range of 450 to 550 micrometers. Additionally, features may include horizontal or vertical integration of the modular modulator, modular amplifier, and modular transceiver chips.Additionally, features may include modular modulators, modular amplifiers, and modular transceiver chips that are part of an autonomous vehicle or an autonomous vehicle control system.

[0005] According to another aspect of the subject matter described in this disclosure, a LIDAR sensor system for a vehicle is included. The LIDAR sensor system includes: a seed laser configured to output a beam; a modulator coupled to the seed laser to receive the beam from the seed laser and modulate the beam to generate a modulated beam; an amplifier coupled to the modulator to receive the modulated beam from the modulator and generate an amplified beam; and a transceiver coupled to the modulator and the amplifier, the transceiver being configured to process and emit the amplified beam via surface emission in a direction relative to the transceiver, and to receive and process reflected beams from objects in the environment in which the vehicle is located. In some embodiments of this disclosure, an autonomous vehicle control system may include the LIDAR sensor system as described herein and one or more processors configured to use the reflected beams to determine at least one of range to an object or velocity of the object, and to control the operation of the autonomous vehicle in response to at least one of range or velocity. In some embodiments of this disclosure, the autonomous vehicle may include the LIDAR sensor system as described herein, a steering system, a braking system, and a vehicle controller. The vehicle controller may include one or more processors configured to use a reflected beam to determine at least one of the range to an object or the speed of the object, and to control the operation of at least one of the steering system and the braking system in response to at least one of the range or the speed.

[0006] These and other implementations may each optionally include one or more of the following features. For example, a feature may include a transceiver comprising an optical window through which an amplified beam is emitted and a reflected beam is received. A feature may also include surface emission comprising emitting the amplified beam perpendicularly from the surface of the transceiver. For example, a feature may also include a transceiver that processes the reflected beam from an object to detect a photocurrent and couples the detected photocurrent to a transimpedance amplifier. In another example, a feature may include a modulator and a seed laser integrated into a seed laser assembly, with the seed laser assembly mounted on a first base and the transceiver mounted on a second base for aligning the height of the seed laser and the transceiver for optical coupling. In various examples, a feature may include an amplifier comprising a semiconductor optical amplifier, and the semiconductor optical amplifier being integrated with a U-shaped passive component for optical amplification. In another example, a feature may include an amplifier comprising a tapered semiconductor optical amplifier configured to receive a modulated beam from a modulator and generate an amplified beam through stimulated emission. In one example, the amplifier may include at least one of indium phosphide (InP), gallium arsenide (GaAs), indium monoarsenide (InAs), gallium nitride (GaN), indium antimonide (InSb), or rare-earth-doped materials. For example, features may include a modulator optically coupled to the amplifier via a first lens array that compensates for a height difference between a first height of the modulator's pedestal and a second height of the amplifier's pedestal, and the amplifier optically coupled to a transceiver via a second lens array. In one example, the first lens array, the amplifier, and the second lens array are integrated into a single chip. In another example, other features may include a beamsplitter coupling the output of the modulator to the input of the amplifier, and the beamsplitter comprising 1 to 16 beamsplitters having a spacing in the range of 450 to 550 micrometers. In various examples, features may also include a first lens array coupling the output of the beamsplitter to the input of the amplifier, the beamsplitter comprising a plurality of 1 to 4 beamsplitter chips having a spacing in the range of 450 to 550 micrometers, and the first lens array comprising four lenses having a spacing in the range of 450 to 550 micrometers. Additionally, the features may include each of the modulator, amplifier, and transceiver being structurally modular and horizontally aligned for optical coupling, and the optical ports on each of the modulator, amplifier, and transceiver being horizontally aligned for optical coupling with matched spacing, matched optical mode dimensions, and matched sectional angles. In another example, the features may include each of the modulator, amplifier, and transceiver being structurally modular and vertically aligned for optical coupling.

[0007] Those skilled in the art will understand that the invention is illustrative only and is not intended to be limiting in any way. Any feature described herein may be used in conjunction with any other feature, and any subset of such features may be combined according to various embodiments. Other aspects, inventive features, and advantages of the apparatus and / or process described herein, as defined only by the claims, will become apparent from the detailed description set forth herein and taken in conjunction with the accompanying drawings. Furthermore, the language used in this disclosure has been chosen primarily for readability and guidance purposes and does not limit the scope of the subject matter disclosed herein. Attached Figure Description

[0008] The embodiments are shown in the accompanying drawings by way of example rather than by way of limitation, wherein the same reference numerals refer to similar elements, and wherein:

[0009] Figure 1A This is a block diagram illustrating an example of a system environment for an autonomous vehicle according to some implementations.

[0010] Figure 1B This is a block diagram illustrating an example of a system environment for an autonomous commercial truck transport vehicle according to some implementations.

[0011] Figure 1C This is a block diagram illustrating an example of a system environment for an autonomous commercial truck transport vehicle according to some implementations.

[0012] Figure 1D This is a block diagram illustrating an example of a system environment for an autonomous commercial truck transport vehicle according to some implementations.

[0013] Figure 2 This is a block diagram illustrating an example of a LIDAR sensor system for autonomous vehicles according to some embodiments.

[0014] Figure 3 This is a high-level block diagram illustrating example components of a LIDAR sensor system for autonomous vehicles according to some embodiments.

[0015] Figure 4 This is a high-level block diagram illustrating example modular components of a horizontally integrated LIDAR sensor system for autonomous vehicles according to some embodiments.

[0016] Figure 5 This is a high-level block diagram illustrating example modular components of a horizontally or vertically integrated LIDAR sensor system for autonomous vehicles according to some embodiments.

[0017] Figure 6 This is a high-level block diagram showing an example plan view of modular components of a LIDAR sensor system for autonomous vehicles according to some embodiments.

[0018] Figure 7 This is a cross-sectional view illustrating an example integrated chip package of a modular LIDAR sensor system for autonomous vehicles according to some embodiments.

[0019] It should be understood that alternative implementations of the structures and methods shown herein may be used without departing from the principles described herein. Detailed Implementation

[0020] According to certain aspects, the modular LIDAR sensor system 300 includes a seed laser 308, a modular modulator 306, a modular amplifier 304, and a modular transceiver chip 302. The LIDAR sensor system 300 is advantageous because each of these components 302, 304, 306, and 308 has a modular design. This modular design is particularly advantageous because each component is a discrete integrated circuit, and the discrete integrated circuits are optically coupled via microlenses. Due to this modularity, the modular LIDAR sensor system 300 overcomes the disadvantages of the prior art described above, as each discrete integrated circuit offers a much higher yield for each modular component. This modular design allows for individual testing of the effectiveness of each component in various aspects. Furthermore, this modular design provides greater configuration flexibility because different versions of any of the modular modulator 306, modular amplifier 304, or modular transceiver chip 302 can be combined with other modular components. In some embodiments, the LIDAR sensor system 300 may further include an integrated chip package for the LIDAR sensor, the integrated chip package defining the configuration of optical components to provide a path for optical signals to travel in and out of the LIDAR sensor and dissipate heat generated by the optical components to improve performance. The modular transceiver chip 302 may be configured to emit a light beam perpendicularly from a first surface of the modular transceiver chip 302 through an optical window and to receive a reflected light beam from a target through the optical window.

[0021] In the following description, numerous specific details are set forth for illustrative purposes to provide a thorough understanding of various aspects of different exemplary embodiments. Note that any particular exemplary embodiment may be practiced in various cases without all the specific details and / or with variations, substitutions, and combinations of the various features and elements described herein. Reference will now be made in detail to embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. Where possible, the same reference numerals are used in the drawings and description to refer to the same or similar parts.

[0022] Furthermore, relative terms such as “lower” or “bottom” or “rear” or “below” and “upper” or “top” or “front” or “above” may be used herein to describe the relationship between one element and another, as illustrated in the figures. It should be understood that, in addition to the orientations depicted in the figures, the relative terms are intended to cover different orientations of the device. For example, if the device in one of the figures is flipped, an element described as being on the “lower” side of other elements will be oriented on the “upper” side of other elements. Thus, depending on the specific orientation of the figure, the exemplary term “lower” may cover both “lower” and “upper” orientations. Similarly, if the device in one of the figures is flipped, an element described as being “below” or “under” other elements will be oriented “above” other elements. Thus, the exemplary terms “below” or “below” may cover both “above” and “below” orientations.

[0023] Referring to the accompanying drawings, the same reference numerals denote the same parts throughout several views. Figure 1A An example of a system environment 100A for an autonomous vehicle 111A in which various technologies disclosed herein may be implemented is shown. For example, vehicle 111A may include: a power system 102 comprising a prime mover 104 powered by energy source 106 and capable of powering a transmission system 108; and a control system 110 comprising steering control 112, power system control 114, and braking control 116. Vehicle 111A may be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or goods and capable of traveling over land, and it should be understood that the aforementioned components 102 to 116 may vary widely depending on the type of vehicle in which these components are utilized.

[0024] For simplicity, the embodiments discussed below focus on wheeled land vehicles, such as cars, vans, trucks, buses, etc. In such embodiments, the prime mover 104 may include one or more electric motors and / or internal combustion engines (etc.). Energy source 106 may include, for example, a fuel system (e.g., providing gasoline, diesel, hydrogen, etc.), a battery system, solar panels or other renewable energy sources and / or a fuel cell system. The drivetrain 108 includes wheels and / or tires and a transmission and / or any other mechanical drive components adapted to convert the output of the prime mover 104 into vehicle motion, and one or more brakes configured to controllably stop or slow the vehicle 111A, and directional or steering components adapted to control the trajectory of the vehicle 111A (e.g., rack and pinion steering linkages that enable one or more wheels of the vehicle 111A to pivot about a generally vertical axis to change the angle of the wheel relative to the plane of rotation of the vehicle's longitudinal axis). In some embodiments, a combination of powertrain and energy source may be used (e.g., in the case of an electric / gasoline hybrid vehicle), and in other embodiments, multiple electric motors (e.g., dedicated to individual wheels or axles) may be used as the prime mover 104. In the case of a hydrogen fuel cell implementation, the prime mover 104 may include one or more electric motors, and the energy source 106 may include a fuel cell system powered by hydrogen fuel.

[0025] Steering control 112 may include one or more actuators and / or sensors for controlling and receiving feedback from steering or directional components to enable vehicle 111A to follow a desired trajectory. Powertrain control 114 may be configured to control the output of powertrain 102, such as controlling the output power of prime mover 104, controlling the gear position of the transmission in drivetrain 108, etc., thereby controlling the speed and / or direction of vehicle 111A. Braking control 116 may be configured to control one or more brakes that slow or stop vehicle 111A, such as disc brakes or drum brakes coupled to the wheels of the vehicle.

[0026] Other vehicle types, including but not limited to all-terrain or tracked vehicles and construction equipment, may utilize different power systems, transmission systems, energy sources, steering control, powertrain control, and braking control. Furthermore, in some embodiments, certain components may be combined; for example, vehicle steering control may be handled primarily by altering the output of one or more prime movers. Therefore, the embodiments disclosed herein are not limited to the specific applications of the techniques described herein in autonomous wheeled land vehicles.

[0027] In the illustrated embodiment, various levels of autonomous control, including fully or semi-autonomous control of vehicle 111A, can be implemented in vehicle control system 120, which may include one or more processors 122 and one or more memories 124, wherein each processor 122 is configured to execute program code instructions 126 stored in memory 124. The processors may include, for example, a graphics processing unit (“GPU”) and / or a central processing unit (“CPU”).

[0028] Sensor 130 may include various sensors suitable for collecting information from the vehicle's surrounding environment for use in controlling the operation of vehicle 111A. For example, sensor 130 may include one or more detection and ranging sensors (e.g., RADAR sensor 134, LIDAR sensor 136, or both), 3D positioning sensors 138, such as satellite navigation systems like GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), BeiDou Navigation Satellite System (BDS), Galileo, compasses, etc. The 3D positioning sensor 138 can be used to determine the vehicle's position on Earth using satellite signals. Sensor 130 may optionally include a camera 140 and / or an IMU (Inertial Measurement Unit) 142. Camera 140 may be a single-image or stereo camera and can record still and / or video images. IMU 142 may include multiple gyroscopes and accelerometers capable of detecting linear and rotational motion of vehicle 111A in three directions. One or more encoders 144, such as wheel encoders, can be used to monitor the rotation of one or more wheels of vehicle 111A. In some embodiments, LIDAR sensor 136 may include the structure of a silicon photonic device for a coherent LIDAR system, as described in detail below.

[0029] The output of sensor 130 can be provided to a set of control subsystems 150, including a positioning subsystem 152, a perception subsystem 154, a planning subsystem 156, and a control subsystem 158. The positioning subsystem 152 is primarily responsible for accurately determining the position and orientation (sometimes referred to as "attitude" or "attitude estimation") of vehicle 111A within its surrounding environment, and typically within a reference frame. The perception subsystem 154 is primarily responsible for detecting, tracking, and / or identifying objects within the environment surrounding vehicle 111A. Machine learning models, according to some embodiments, can be used for object tracking. The planning subsystem 156 is primarily responsible for planning the trajectory or path of vehicle 111A's movement over a given time frame, given a desired destination and static and moving objects within the environment. Machine learning models, according to some embodiments, can be used for vehicle trajectory planning. The control subsystem 158 is primarily responsible for generating appropriate control signals to control various controls within the vehicle control system 120 to achieve the planned trajectory of vehicle 111A. Similarly, machine learning models can be used to generate one or more signals to control the autonomous vehicle 111A to achieve the planned trajectory.

[0030] Will understand, Figure 1A The assembly of components for the vehicle control system 120 illustrated in the diagram is merely an example. In some embodiments, individual sensors may be omitted. Additionally or alternatively, in some embodiments, Figure 1A Multiple sensors of the same type illustrated in the diagram can be used for redundancy and / or to cover different areas around the vehicle. In addition to the sensors described above, other types of additional sensors may be used to provide actual sensor data related to the operation and environment of the wheeled land vehicle. Similarly, in other embodiments, different types and / or combinations of control subsystems may be used. Furthermore, although subsystems 152 to 158 are illustrated as separate from processor 122 and memory 124, it should be understood that in some embodiments, some or all of the functionality of subsystems 152 to 158 may be implemented using program code instructions 126 residing in one or more memories 124 and executed by one or more processors 122, and in some instances, these subsystems 152 to 158 may be implemented using the same processor and / or memory. Subsystems may be implemented, at least in part, using various special-purpose circuit logics, various processors, various field-programmable gate arrays (“FPGAs”), various application-specific integrated circuits (“ASICs”), various real-time controllers, etc., and as described above, multiple subsystems may utilize circuit systems, processors, sensors, and / or other components. Furthermore, various components in the vehicle control system 120 may be networked in various ways.

[0031] In some embodiments, vehicle 111A may further include an auxiliary vehicle control system (not shown), which can serve as a redundancy or backup control system for vehicle 111A. In some embodiments, the auxiliary vehicle control system can fully operate the autonomous vehicle 111A in the event of an adverse event detected in the primary vehicle control system 120, while in other embodiments, the auxiliary vehicle control system may have only limited functionality, such as performing a controlled stop of vehicle 111A in response to an adverse event detected in the primary vehicle control system 120. In still other embodiments, the auxiliary vehicle control system may be omitted.

[0032] Typically, different architectures can be used to implement this. Figure 1A The various components illustrated in the diagram represent various combinations of software, hardware, circuit logic, sensors, networks, etc. For example, each processor can be implemented as a microprocessor, and each memory can represent a random access memory (“RAM”) device, including main memory and any supplementary levels of memory such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), read-only memory, etc. Additionally, each memory can be considered to include memory storage devices physically located elsewhere in vehicle 111A, such as any cache memory in the processor, and any storage capacity used as virtual memory, such as stored in a mass storage device or on another computer controller. Figure 1A One or more processors 122 or completely independent processors illustrated herein can be used to implement additional functions in the vehicle 1A beyond the purpose of autonomous control, such as controlling the entertainment system, operating doors, lights, convenience features, etc.

[0033] Additionally, for additional storage, vehicle 111A may include one or more mass storage devices, such as removable disk drives, hard disk drives, direct access storage devices (“DASD”), optical disc drives (e.g., CD drives, DVD drives, etc.), solid-state storage drives (“SSD”), network-attached storage, storage area networks, and / or tape drives, etc.

[0034] In addition, vehicle 100 may include a user interface 118 for enabling vehicle 111A to receive multiple inputs from a user or operator and generate outputs for the user or operator, such as one or more displays, touchscreens, voice and / or gesture interfaces, buttons, and other tactile controls. Alternatively, user input may be received via another computer or electronic device (e.g., via an application on a mobile device or via a web interface).

[0035] In addition, vehicle 111A may include one or more network interfaces (e.g., network interface 162) adapted to communicate with one or more networks 176 to allow information communication with other computers and electronic devices (including, for example, a central service, such as a cloud service), from which vehicle 111A receives information including trained machine learning models and other data for its autonomous control. The one or more networks 176 may be, for example, communication networks and include one or more wide area networks (“WAN”) such as the Internet, one or more local area networks (“LAN”) such as Wi-Fi LAN, mesh networks, etc., and one or more bus subsystems. The one or more networks 176 may optionally utilize one or more standard communication technologies, protocols, and / or inter-process communication technologies. In some embodiments, data collected by one or more sensors 130 may be uploaded to computing system 172 via network 176 for additional processing. In the illustrated embodiment, vehicle 111A may communicate with computing system 172 via network 176 and signal line 178. In some embodiments, computing system 172 is a cloud-based computing device. Additionally, refer to... Figure 2 The processing of autonomous vehicle data by a computing system 172 according to many embodiments is described.

[0036] Figure 1A Each processor illustrated herein, as well as the various additional controllers and subsystems disclosed herein, typically operates under the control of an operating system and executes or otherwise depends on various computer software applications, components, programs, objects, modules, data structures, etc., as described in more detail below. Furthermore, the various applications, components, programs, objects, modules, etc., may also execute, for example, on one or more processors in another computer (e.g., computing system 172) coupled to vehicle 100 via network 176 in a distributed, cloud-based, or client-server computing environment, wherein the processing required to implement the functionality of the computer program can be distributed across multiple computers and / or services via the network.

[0037] Generally, routines executed to implement the various embodiments described herein, whether implemented as part of an operating system or as a particular application, component, program, object, module, or sequence of instructions, or even a subset thereof, will be referred to herein as "program code." Program code typically comprises one or more instructions that reside in various memories and storage devices at various times and, when read and executed by one or more processors, perform steps necessary to carry out the steps or elements embodying various aspects of this disclosure. Furthermore, while embodiments have been and are described below in the context of fully functional computers and systems, it should be understood that the various embodiments described herein can be distributed as program products in various forms, and embodiments can be implemented regardless of the specific type of computer-readable medium used to actually perform the distribution.

[0038] Examples of computer-readable media include tangible, non-transitory media such as volatile and non-volatile memory devices, floppy disks and other removable disks, solid-state drives, hard disk drives, magnetic tapes and optical discs (e.g., CD-ROMs, DVDs, etc.).

[0039] Furthermore, the various program codes described below can be identified based on the application that implements the program code in its inherent specific implementation. However, it should be understood that any particular program nomenclature used below is for convenience only, and therefore this disclosure should not be limited to use only in any particular application identified and / or implied by such nomenclature. Moreover, given the numerous common ways in which a given computer program can be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functionality can be allocated across various software layers (e.g., operating systems, libraries, APIs, applications, applets, etc.) residing within a typical computer, it should be understood that this disclosure is not limited to the specific organization and allocation of program functionality described herein.

[0040] Figure 1A The example environments illustrated herein are not intended to limit the implementations disclosed herein. In practice, other alternative hardware and / or software environments can be used without departing from the scope of the implementations disclosed herein.

[0041] Trucks may include lidar systems (e.g., Figure 1A The vehicle control system 120 in Figure 2(e.g., lidar system 201). In some embodiments, a lidar system can use frequency modulation to encode an optical signal and use optics to scatter the encoded optical signal into free space. By detecting the frequency difference between the encoded optical signal and the returned signal reflected from the object, a frequency-modulated (FM) lidar system can determine the position of the object and / or accurately measure the velocity of the object using the Doppler effect. FM lidar systems can use continuous waves (referred to as "FMCW lidar" or "coherent FMCW lidar") or quasi-continuous waves (referred to as "FMQW lidar"). Lidar systems can use phase modulation (PM) to encode an optical signal and use optics to scatter the encoded optical signal into free space.

[0042] For automotive and / or commercial truck applications, FM or phase modulation (PM) lidar systems can offer significant advantages over traditional lidar systems. Firstly, in some instances, objects (e.g., pedestrians wearing dark clothing) may have low reflectivity because they reflect only a small amount (e.g., 10% or less) of the light hitting the object back to the sensor of the FM or PM lidar system (e.g., Figure 1A (Sensor 130 in the system). In other instances, an object (e.g., a shiny road sign) may have a high reflectivity (e.g., above 10%) because it will reflect a large amount of light hitting the object back to the sensor of the FMlidar system.

[0043] Regardless of an object's reflectivity, the FM lidar system can detect (e.g., classify, identify, discover, etc.) objects at much greater distances (e.g., twice as many) compared to traditional lidar systems. For example, the FM lidar system can detect low-reflectivity objects beyond 300 meters and high-reflectivity objects beyond 400 meters.

[0044] To achieve this improvement in detection capability, the FMlidar system can use sensors (e.g., Figure 1A(Sensor 130 in the example). In some implementations, these sensors may be single-photon sensitive, meaning they can detect the smallest possible amount of light. While FM lidar systems can use infrared wavelengths (e.g., 950 nm, 1550 nm, etc.) in some applications, they are not limited to the infrared wavelength range (e.g., near-infrared: 800 nm to 1500 nm; mid-infrared: 1500 nm to 5600 nm; and far-infrared: 5600 nm to 1,000,000 nm). By operating within the infrared wavelength range, FM or PM lidar systems can broadcast stronger light pulses or beams while meeting eye safety standards. Conventional lidar systems are typically not single-photon sensitive and / or operate only within the near-infrared wavelength range, thus requiring them to limit their light output (and distance detection capability) for eye safety reasons.

[0045] Therefore, by detecting objects at greater distances, FM lidar systems can have more time to react to unexpected obstacles. In fact, even a few milliseconds of extra time can improve safety and comfort, especially for heavy vehicles (such as commercial trucks) driven at highway speeds.

[0046] Another advantage of FM lidar systems is their ability to provide accurate velocity for each data point instantaneously. In some implementations, velocity measurement is accomplished using the Doppler effect, which shifts the frequency of light received from an object based on at least one of the radial velocity (e.g., the direction vector between the detected object and the sensor) or the frequency of the laser signal. For example, for velocities encountered on roads less than 100 meters per second (m / s), this shift at a wavelength of 1550 nanometers (nm) totals less than a 130 MHz frequency shift. This frequency shift is so small that it is difficult to detect directly in the optical domain. However, by using coherent detection in FMCW, PMCW, or FMQW lidar systems, the signal can be converted to the RF domain, allowing the frequency shift to be calculated using various signal processing techniques. This enables autonomous vehicle control systems to process incoming data much faster.

[0047] Instantaneous velocity calculations also make it easier for FM lidar systems to identify distant or sparse data points as objects and / or track how these objects are moving over time. For example, FM lidar sensors (e.g., Figure 1A The sensor 130 in the system may receive only a few returns from an object 300 meters away (e.g., hit), but if these returns give a speed value of interest (e.g., moving toward the vehicle at a speed >70 mph), the FMlidar system and / or the autonomous vehicle control system can determine the corresponding weights of the probabilities associated with the object.

[0048] The faster identification and / or tracking of objects by the FM lidar system gives autonomous vehicle control systems more time to maneuver the vehicle. A better understanding of how fast an object is moving also allows autonomous vehicle control systems to plan better responses.

[0049] Another advantage of FM lidar systems is their reduced static interference compared to traditional lidar systems. Traditional lidar systems, designed to be highly sensitive to light, typically perform poorly in bright sunlight. These systems are also susceptible to crosstalk (e.g., when sensors are confused by each other's light pulses or beams) and self-interference (e.g., when sensors are confused by their own previous light pulses or beams). To overcome these drawbacks, vehicles using traditional lidar systems typically require additional hardware, complex software, and / or more computing power to manage this "noise."

[0050] In contrast, FM lidar systems do not suffer from these types of problems because each sensor is specifically designed to respond only to its own optical characteristics (e.g., beams, waves, pulses). If the returned light does not match the timing, frequency, and / or wavelength of the originally emitted light, the FM sensor can filter (e.g., remove, ignore, etc.) that data point. Therefore, FM lidar systems produce (e.g., generate, export, etc.) more accurate data with fewer hardware or software requirements, resulting in safer and smoother driving.

[0051] Finally, FM lidar systems are more scalable than traditional lidar systems. As more autonomous vehicles (such as cars and commercial trucks) appear on the road, vehicles powered by FM lidar systems may not have to deal with interference issues caused by sensor crosstalk. Furthermore, FM lidar systems use less peak optical power than traditional lidar sensors. Therefore, some or all of the optical components of an FM lidar can be manufactured on a single chip, which has its own advantages, as discussed in this paper.

[0052] Figure 1BThis is a block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to some embodiments. Environment 100B includes a commercial truck 180B for hauling cargo 182B. In some embodiments, the commercial truck 180B may include a vehicle configured for long-haul freight transport, regional freight transport, intermodal freight transport (i.e., where a road-based vehicle is used as one of a variety of transport modes to move cargo), and / or any other road-based freight transport application. The commercial truck 180B may be a flatbed truck, a refrigerated truck (e.g., a frozen truck), a ventilated van (e.g., a dry van), a mobile truck, etc. Cargo 182B may be goods and / or products. The commercial truck 180B may include trailers for carrying cargo 182B, such as flatbed trailers, low-floor trailers, ladder trailers, retractable flatbed trailers, side trailers, etc.

[0053] Environment 100B includes object 111B (in Figure 1B (The vehicle shown is another vehicle) within a distance of 30 meters or less from the truck.

[0054] Commercial truck 180B may include lidar system 184B (e.g., FM lidar system, Figure 1A The vehicle control system 120 in Figure 2 The lidar system 201 (etc.) is used to determine the distance to object 111B and / or measure the velocity of object 111B. Although Figure 1B A lidar system 184B is shown mounted on the front of a commercial truck 180B, but the number of lidar systems and the mounting areas of the lidar systems on the commercial truck are not limited to a specific number or specific area. The commercial truck 180B may include any number of lidar systems 184B (or components thereof, such as sensors, modulators, coherent signal generators, etc.) mounted in any area of ​​the commercial truck 180B (e.g., front, rear, side, top, bottom, under, and / or bottom) to facilitate the detection of objects in any free space relative to the commercial truck 180B.

[0055] As shown in the figure, the lidar system 184B in environment 100B can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a short distance (e.g., 30 meters or less) from the commercial truck 180B.

[0056] Figure 1C This is a block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to some embodiments. Environment 100C includes the same components included in environment 100B (e.g., commercial truck 180B, cargo 182B, lidar system 184B, etc.).

[0057] Environment 100C includes object 111C (in Figure 1C The lidar system 184B in environment 100C can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a distance (e.g., 100 meters) from commercial truck 180B.

[0058] Figure 1D This is a block diagram illustrating an example of a system environment for an autonomous commercial truck vehicle according to some embodiments. Environment 100D includes the same components included in environment 100B (e.g., commercial truck 180B, cargo 182B, lidar system 184B, etc.).

[0059] Environment 100D includes object 111D (in Figure 1D The image shows another vehicle (represented in the image) within a distance of more than 150 meters from the commercial truck 180B. As shown, the lidar system 184B in environment 100D can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a distance (e.g., 300 meters) from the commercial truck 180B.

[0060] In commercial truck applications, effective object detection across all ranges is crucial due to the increased weight and the correspondingly longer stopping distances required for such vehicles. Because of the aforementioned advantages, FM lidar systems (e.g., FMCW and / or FMQW systems) or PM lidar systems are well-suited for commercial truck applications. Therefore, commercial trucks equipped with such systems can have enhanced capabilities to safely move both people and goods across short or long distances, thereby improving not only the safety of the commercial truck but also the safety of surrounding vehicles. In various implementations, such FM or PM lidar systems can be used in the following scenarios: semi-autonomous applications, where the commercial truck has a driver and some functions of the commercial truck are operated autonomously using the FM or PM lidar system; or fully autonomous applications, where the commercial truck is operated entirely by the FM or lidar system alone or in combination with other vehicle systems.

[0061] In lidar systems using CW modulation, the modulator continuously modulates the laser. For example, if the modulation period is 10 seconds, the input signal is modulated over the entire 10 seconds. Conversely, in lidar systems using quasi-CW modulation, the modulator modulates the laser to have both active and inactive portions. For example, for a 10-second period, the modulator modulates the laser only for 8 seconds (sometimes called the "active portion"), but not for 2 seconds (sometimes called the "inactive portion"). By doing so, the lidar system is able to reduce power consumption for those 2 seconds because the modulator does not have to provide a continuous signal.

[0062] In frequency modulated continuous wave (FMCW) lidar for automotive applications, it may be advantageous to operate the lidar system using quasi-CW modulation, where FMCW measurement and signal processing methods are employed, but the optical signal is not always on (e.g., enabled, powered on, transmitted, etc.). In some implementations, quasi-CW modulation can have a duty cycle equal to or greater than 1% and up to 50%. If the energy that is in a closed state (e.g., disabled, powered off, etc.) can be consumed during the actual measurement time, then there can be an improvement in signal-to-noise ratio (SNR) and / or a reduction in signal processing requirements to coherently integrate all energy over a longer timescale.

[0063] Figure 2 This is a block diagram illustrating an example environment for a lidar sensor system for an autonomous vehicle according to some embodiments. Environment 200 includes a lidar sensor system 201, which includes a transmit (Tx) path and a receive (Rx) path. The Tx path includes one or more Tx input / output ports (…). Figure 2 (not shown in the image), and the Rx path includes one or more Rx input / output ports ( Figure 2 (Not shown in the image).

[0064] In some embodiments, the semiconductor substrate and / or semiconductor package may include a Tx path and an Rx path. In some embodiments, the semiconductor substrate and / or semiconductor package may include at least one of a silicon photonics circuit, a programmable logic controller (PLC), or a III-V semiconductor circuit.

[0065] In some implementations, the first semiconductor substrate and / or the first semiconductor package may include a Tx path, and the second semiconductor substrate and / or the second semiconductor package may include an Rx path. In some arrangements, Rx input / output ports and / or Tx input / output ports may occur (or be formed / set / positioned / placed) along one or more edges of one or more semiconductor substrates and / or semiconductor packages.

[0066] Environment 200 includes one or more transmitters 216 and one or more receivers 222.

[0067] Environment 200 includes one or more optics 210 (e.g., oscillating scanners, unidirectional scanners, Risley prisms, circulator optics, and / or beam collimators, etc.) coupled to lidar system 201. In some embodiments, one or more optics 210 may be coupled to a Tx path via one or more Tx input / output ports. In some embodiments, one or more optics 210 may be coupled to an Rx path via one or more Rx input / output ports.

[0068] Environment 200 includes a vehicle control system 120 coupled to lidar system 201 (e.g., Figure 1A (Vehicle control system 120 in the example). In some embodiments, vehicle control system 120 may be coupled to the Rx path via one or more Rx input / output ports.

[0069] The Tx path may include a laser source 202, modulator 204A, modulator 204B, amplifier 206, and one or more transmitters 216. The Rx path may include one or more receivers 222, mixer 208, detector 212, transimpedance amplifier (TIA) 214, and one or more analog-to-digital converters (ADCs). Although Figure 2 Only a selected number of components and only one input / output channel are shown; however, environment 200 may include any number of components and / or input / output channels (in any combination) interconnected in any arrangement to facilitate multiple functions of the combined lidar system to support vehicle operation.

[0070] Laser source 202 can be configured to generate an optical signal (or beam) derived from (or associated with) a local oscillator (LO) signal. In some embodiments, the optical signal may have an operating wavelength equal to or substantially equal to 1550 nanometers. In some embodiments, the optical signal may have an operating wavelength between 1400 nanometers and 1440 nanometers.

[0071] Laser source 202 can be configured to provide an optical signal to modulator 204A, modulator 204A being configured to provide an optical signal based on a first radio frequency (RF) signal (in... Figure 2The optical signal (shown as "RF1") is modulated using continuous wave (CW) modulation or quasi-CW modulation to modulate its phase and / or frequency to generate a modulated optical signal. Modulator 204A can be configured to send the modulated optical signal to amplifier 206. Amplifier 206 can be configured to amplify the modulated optical signal to generate an amplified optical signal via one or more transmitters 216 to optics 210. One or more transmitters 216 may include one or more optical waveguides or antennas.

[0072] Optical device 210 can be configured to direct amplified optical signals received from the Tx path toward object 218 into the environment within a given field of view, receive return signals reflected back from object 218, and provide the return signals to mixer 208 of the Rx path via one or more receivers 222. The one or more receivers 222 may include one or more optical waveguides or antennas. In some arrangements, transmitter 216 and receiver 222 may constitute one or more transceivers. Figure 2 (Not shown in the image). In some arrangements, one or more transceivers may include monobase transceivers or bibase transceivers.

[0073] Laser source 202 can be configured to provide an LO signal to modulator 204B, modulator 204B being configured to provide a second RF signal (in Figure 2 The phase and / or frequency of the LO signal are modulated using continuous wave (CW) modulation or quasi-CW modulation to generate a modulated LO signal and the modulated LO signal is sent to mixer 208 in the Rx path.

[0074] Mixer 208 can be configured to mix (e.g., combine, multiply, etc.) the modulated LO signal with the return signal to generate a down-converted signal and send the down-converted signal to detector 212. In some arrangements, mixer 208 can be configured to send the modulated LO signal to detector 212.

[0075] Detector 212 can be configured to generate an electrical signal based on the down-converted signal and send the electrical signal to TIA 214. In some arrangements, detector 212 can be configured to generate an electrical signal based on both the down-converted signal and the modulated signal.

[0076] TIA 214 can be configured to amplify electrical signals and send the amplified electrical signals to vehicle control system 120 via one or more ADCs 220.

[0077] In some implementations, the TIA 214 may have a peak noise equivalent power (NEP) of less than 5 picowatts per square root hertz (i.e., 5 x 10⁻¹² watts per square root hertz). In some implementations, the TIA 214 may have a gain between 4 kiloohms and 25 kiloohms.

[0078] In some implementations, detector 212 and / or TIA 214 may have a bandwidth of 3 dB between 80 kHz and 450 MHz.

[0079] The vehicle control system 120 can be configured to determine the distance to the object 218 and / or measure the speed of the object 218 based on one or more electrical signals received from the TIA via one or more ADCs 220.

[0080] In some implementations, modulator 204A and / or modulator 204B may have a bandwidth between 400 MHz and 1000 MHz.

[0081] In some embodiments, modulator 204A may be configured to send a first modulated optical (optical) signal and a second modulated optical (optical) signal to amplifier 206. Amplifier 206 may be configured to amplify the first and second modulated optical signals to generate an amplified optical signal via transmitter 216 to optics 210. Optics 210 may be configured to direct the first and second modulated optical signals received from the Tx path toward object 218 into the environment within a given field of view, receive corresponding first and second return signals reflected back from object 218, and provide the first and second return signals to mixer 208 of the Rx path via receiver 222. Modulator 204B may be configured to generate (1) a first modulated LO signal associated with the first modulated optical signal and (2) a second modulated LO signal associated with the second modulated optical signal, and send the first and second modulated LO signals to mixer 208 of the Rx path. Mixer 208 can be configured to pair a first returned optical signal with a first modulated LO signal (e.g., associate, link, identify, etc.), and mix the first returned optical signal with the first modulated LO signal (e.g., combine, multiply, etc.) to generate a first down-converted signal, and send the first down-converted signal to detector 212. Similarly, mixer 208 can be configured to pair a second returned optical signal with a second modulated LO signal, and mix the second returned optical signal with the second modulated LO signal to generate a second down-converted signal, and send the second down-converted signal to detector 212. Detector 212 can be configured to generate first and second electrical signals based on the first and second down-converted signals, respectively. Vehicle control system 120 can be configured to determine the distance to object 218 and / or measure the speed of object 218 based on the first and second electrical signals received via TIA 214 and ADC 220.

[0082] Figure 3A high-level block diagram illustrating example components 302, 304, 306, and 308 of a modular LiDAR sensor system 300 for autonomous vehicles according to some embodiments is depicted. According to some embodiments, the modular LiDAR sensor system 300 includes a seed laser 308, a modular modulator 306, a modular amplifier 304, and a modular transceiver chip 302. As mentioned above, the modular LiDAR sensor system 300 is particularly advantageous because its modular design allows each of components 302, 304, 306, and 308 to be a discrete integrated circuit optically coupled via microlens. This provides higher yield for the modular components 302, 304, 306, and 308, as well as configurability and ease of assembly for different variations of each modular component 302, 304, 306, and 308. This modular architecture is particularly advantageous because each of the seed laser 308, modular modulator 306, modular amplifier 304, and modular transceiver chip 302 can be individually constructed and tested, and then assembled into the form described below with reference to Figure 4 and 5 The configuration is described. Basically, Figure 3 , Figure 4 and Figure 5 The modular architecture consists of only discrete integrated circuits plus microlenses. This modular architecture eliminates the need for components specific to any fiber optic coupled modular architecture.

[0083] A seed laser 308 is provided to generate a light beam. In some embodiments, the seed laser 308 may be a light source, such as a distributed feedback (DFB) diode laser source. The light or beam from the seed laser 308 may be optically coupled to be input to a modular modulator 306. In some embodiments, the seed laser 308 includes a DFB diode laser source 310 and a microlens assembly 312 coupling the DFB diode laser source 310 to the modular modulator 306. The seed laser 308 is modular because it can be constructed as a single integrated circuit.

[0084] Modular modulator 306 receives the beam generated by the seed laser and generates a modulated optical signal. In some embodiments, modular modulator 306 includes a modulator and a beam splitter (see below). Figure 4 and 5 In some embodiments, the modular modulator 306 performs in-phase and quadrature modulation to generate a modulated beam. In some embodiments, the modular modulator 306 performs phase modulation to generate a modulated beam. A beam splitter is coupled to the output of the modulator and provides the output of the modular modulator 306. In some embodiments, the beam splitter is a single beam splitter as a passive component integrated with the modulator of the modular modulator 306, as will be referred to below. Figure 4A more detailed description follows. In some implementations, the beam splitter is a plurality of beam splitters, as will be referred to below. Figure 5 A more detailed description follows. The modular modulator 306 is modular because it can be constructed as a single integrated circuit.

[0085] In some embodiments, the seed laser 308 and the modular modulator 306 may be integrated to form a seed laser assembly 314. In some embodiments, the seed laser assembly 314 is mounted on a first submount, and a coupled modular transceiver chip 302 is mounted on a second submount for aligning the heights of the seed laser assembly 314 and the modular transceiver chip 302 for optical coupling.

[0086] Modular amplifier 304 is one or more semiconductor optical amplifiers (SOAs). In some embodiments, modular amplifier 304 is one or more tapered semiconductor optical amplifiers (TSOAs). In some embodiments, modular amplifier 304 is one or more SOA array chips. Each SOA array chip includes an integrated U-turn and other passive components for optical amplification. In some embodiments, the SOA array chip may be an integrated photonic device based on III-V semiconductors, wherein all its components are made of III-V material and formed / disposed on a single substrate made of III-V material. Furthermore, in some embodiments, each SOA array chip may include four to five channels and is configured to amplify a light beam by stimulated emission. Modular amplifier 304 is optically coupled to modular modulator 306 via microlenses (not shown). Similarly, modular amplifier 304 is optically coupled to provide amplified signals to modular transceiver chip 302 via microlenses (not shown). Reference will be made below. Figure 4 and 5 A more detailed description of the optical coupling is provided.

[0087] In some embodiments, the modular silicon photonics (SiPho) transceiver chip 302 includes at least one of silicon photonics circuitry, a programmable logic controller (PLC), or a III-V semiconductor circuit. The modular SiPho transceiver chip 302 uses a modular amplifier 304 to process the coupled light. The modular SiPho transceiver chip 302 includes a plurality of coherent pixels that process the output of the modular amplifier 304 and emit light from the surface of the modular SiPho transceiver chip 302 via an optical window of the integrated chip package. The modular SiPho transceiver chip 302 processes light collected from reflections from a target and couples the detected photocurrent to a transimpedance amplifier (not shown). The transimpedance amplifier converts the photocurrent into a voltage, which is then coupled out from the integrated chip package.

[0088] Figure 4 This is a high-level block diagram illustrating example modular components of a horizontally integrated LIDAR sensor system 400 for autonomous vehicles according to some embodiments. As shown, the LIDAR sensor system 400 includes: a seed laser 308, a modular modulator 306, an integrated seed microlens 402, a beam splitter 404, a first microlens array 406a, a TSOA array 408, a second microlens array 406b, and a modular SiPho transceiver chip 302.

[0089] In this embodiment, the seed laser 308, the modular modulator 306, and the modular SiPho transceiver chip 302 have the same characteristics as those referenced above. Figure 3 The similar structure, form, and function described herein will not be repeated here. The modular modulator 306 is coupled to the beam splitter 404 via an integrated seed microlens 402. In other words, the seed laser 308, the modular modulator 306, and the integrated seed microlens 402 can be integrated into a single integrated circuit. This is achieved using a p-up semiconductor structure. Figure 4 An example configuration of this integration is shown in the cross-section on the left side of these components 306, 308, and 402.

[0090] Beam splitter 404 is a 1 to n beam splitter that splits the optical signal output from modular modulator 306 into n signals via integrated seed microlens 402. In some embodiments, the core pitch of beam splitter 404 is in the range of 450 to 550 micrometers. In some embodiments, beam splitter 404 is a 1 to 16 beam splitter with a core pitch of 500 μm. In some embodiments, beam splitter 404 is a 1 to 32 beam splitter with a core pitch of 500 μm. In some embodiments, beam splitter 404 is a passive optical beam splitter. In some embodiments, beam splitter 404 is formed on one or more integrated circuits. Figure 4 An example configuration for this integration is shown in the cross-section on the left side of components 402 and 404, which has a p-down semiconductor structure.

[0091] A first microlens array 406a is used to optically couple the output of beam splitter 404 to TSOA array 408. The first microlens array 406a includes a microlens for each signal output by beam splitter 404. In some embodiments, the first microlens array 406a includes 16 microlenses with a 500 μm pitch. In some embodiments, the first microlens array 406a includes 32 microlenses with a 500 μm pitch. Each lens in the first microlens array 406a couples the output of beam splitter 404 to a corresponding TSOA in TSOA array 408. In some embodiments, seed microlens 402 and the first microlens array 406 compensate for the height difference between a first height of the pedestal of modular modulator 306 and a second height of the pedestal of modular amplifier 408.

[0092] The TSOA array 408 has the same number of TSOAs as the output signals from the beamsplitter 404. In other words, for each signal output by the beamsplitter 404, there is a corresponding TSOA. In some embodiments, the beamsplitter 404 outputs 16 optical signals, and the TSOA array 408 includes 16 TSOAs. In some embodiments, the beamsplitter 404 outputs 32 optical signals, and the TSOA array 408 includes 32 TSOAs. In some embodiments, the TSOA array 408 includes 16 aperture bars or a plurality of individual bars, wherein the array includes 16 TSOAs. As described below, the TSOA array includes dual-sided cooling and a substrate real estate on one side for flatness. In some embodiments, the TSOAs have a spacing of 500 μm. It should be understood that in other embodiments, the array may be other types of SOA. The TSOA array 408 is optically coupled to the beamsplitter 404 via a first microlens array 406a and optically coupled to the modular SiPho transceiver chip 302 via a second microlens array 406b.

[0093] The second microlens array 406b is used to couple the output light of the TSOA array 408 to the modular SiPho transceiver chip 302. The second microlens array 406b includes a microlens for each signal output by the TSOA array 408. Essentially, the second microlens array 406b includes a microlens for each TSOA in the TSOA array 408. In some embodiments, the second microlens array 406b includes 16 microlenses with a 500 μm pitch. In some embodiments, the second microlens array 406b includes 32 microlenses with a 500 μm pitch. Each lens in the second microlens array 406b couples the output of the TSOA to a corresponding input of the modular SiPho transceiver chip 302.

[0094] In some embodiments, the first microlens array 406a, the TSOA array 408, and the second microlens array 406b are formed on a single integrated circuit. Figure 4 The cross-section on the left side of these components 406a, 408 and 406b shows an example configuration for this integration, which has a lower p-type semiconductor structure.

[0095] The modular components 306, 402, 404, 406a, 408, 406b, and 302 described above are horizontally integrated, meaning that each semiconductor chip forming each modular component is stacked on top of each other as shown in the figure. This only requires horizontal alignment of the different components to ensure that light is transferred from one modular component to another as needed for optical coupling. In some implementations, according to Snell's Law, the optical ports on every two aligned chips must be at the same spacing and have matching optical mode sizes and sectional angles.

[0096] Figure 5 This is a high-level block diagram illustrating example modular components of a horizontally or vertically integrated LIDAR sensor system 500 for autonomous vehicles according to some embodiments. The LIDAR sensor system 500 includes: a seed laser 308, a modular modulator 306, multiple seed microlenses 502a-502d, multiple beam splitters 504a-50d, a first multiple microlens array 506a-506d, multiple TSOA chips 508a-508d, a second multiple microlens array 510a-510d, and a modular SiPho transceiver chip 302.

[0097] By dividing the beam splitter 404 into multiple beam splitter chips 504a-504b; dividing the first microlens array 406a into multiple microlens arrays 506a-506d; dividing the TSOA chip 408 into multiple TSOA chips 508a-508d; and dividing the second microlens array 406b into multiple microlens arrays 510a-510d, thus... Figure 5 The LIDAR sensor system 500 is further modularized. This modification to the modular architecture improves yield and reliability by having components that are easier to manufacture. The architecture does require an increased number of modular components with vertical or horizontal alignment to achieve the same architectural output.

[0098] In this embodiment, the seed laser 308, the modular modulator 306, and the modular SiPho transceiver chip 302 have the same characteristics as those referenced above. Figure 3 and Figure 4 The similar structures, forms, and functions described will not be repeated here.

[0099] Modular modulator 306 is coupled to a plurality of microlenses 502a-502d. Each of the plurality of microlenses 502a-502d is optically coupled to a corresponding beamsplitter 504a-504d. For example, microlens 502a couples modular modulator 306 to beamsplitter 504a. Similarly, microlens 502b couples modular modulator 306 to beamsplitter 504b; microlens 502c couples modular modulator 3062 to beamsplitter 504c; and microlens 502d couples modular modulator 3062 to beamsplitter 504c.

[0100] In some implementations, each of the multiple beam splitters 504a-504d is a beam splitter chip. For example comparisons, if desired with... Figure 4 With a similar architecture, and given that modular beam splitter 404 is a 1-16 beam splitter, then multiple beam splitters 504a-504d will each be 1-4 beam splitter chips; therefore... Figure 5 The four beam splitter chips 504a-504d will provide with Figure 4 Each of the multiple modular beam splitters 504a-504d performs the same function as a single modular beam splitter 404. Each of these beam splitters couples a corresponding microlens 502a-502d to a corresponding microlens array 506a-506d. For example, beam splitter 504a couples microlens 502a to microlens array 506a, beam splitter 504b couples microlens 502b to microlens array 506b, beam splitter 504c couples microlens 502c to microlens array 506c; and beam splitter 504d couples microlens 502d to microlens array 506d. It should be understood that... Figure 5 This demonstrates how any number of beamsplitter chips with a smaller beam ratio can be used in a modular manner to replace a single beamsplitter chip with a larger beam ratio.

[0101] As described above, each beam splitter 504a-504d is coupled to a corresponding microlens array 506a-506d. In some embodiments, there are four microlens arrays 506a-506d. Continuing... Figure 4 Modular design and Figure 5In a comparison of modular designs, a single microlens array 406a is replaced by multiple microlens arrays 506a-506d. For example, if a single microlens 406a contains 16 microlenses with a 500 μm pitch and a similar architecture is required, then each of the multiple microlens arrays 506a-506d will contain 4 microlenses with a 500 μm pitch. In some embodiments, the number of microlens arrays and the number of microlenses in each array correspond to the number of signals generated by the beam splitter chips 504a-504d, respectively. Each microlens array in the multiple microlens arrays 506a-506d is then coupled to provide a corresponding optical signal to the corresponding TSOA chips 508a-508d. For example, microlens array 506a provides an optical signal to TSOA chip 508a, microlens array 506b provides an optical signal to TSOA chip 508b, and so on.

[0102] like Figure 5 As shown, each of the multiple TSOA chips 508a-508d amplifies the optical signal received from its corresponding microlens array 506a-506d. In some embodiments, the design includes four TSOA chips 508a-508d. Again, continuing... Figure 4 Modular design and Figure 5 In comparison to the modular design, a single TSOA array 408 is replaced by multiple TSOA chips 508a-508d. Each of the TSOA chips 508a-508d comprises four TSOAs, compared to a single array of TSOA 408. In some embodiments, the multiple TSOA chips 508a-508d may have 16 aperture stripes or many individual stripes, dual-sided cooling, a substrate realm on one side for flatness, and a 500 μm pitch. It should be understood that in other embodiments, the TSOA chips 508a-508d may be other types of SOA.

[0103] Each of the plurality of TSOA chips 508a-508d is optically coupled to the modular SiPho transceiver chip 302 via a corresponding microlens array 510a-510d. A second plurality of microlens arrays 510a-510d may be similar in form and function to the first plurality of microlens arrays 506a-506d, but with corresponding TSOA chips 508a-508d coupled to the modular SiPho transceiver chip 302. In this embodiment of the design, the number of microlens arrays 510a-510d corresponds to the number of TSOA chips 508a-508d.

[0104] Figure 6A high-level block diagram illustrating exemplary plan views of modular components of a LIDAR sensor system 600 for an autonomous vehicle according to some embodiments is shown. Figure 6 A planar implementation and layout of the modular components of this disclosure is shown. In some embodiments, the LIDAR sensor system 600 includes a seed laser assembly 314, a beam splitter 404, a modular SiPho transceiver chip 302, a plurality of semiconductor optical amplifiers 602a-602d, and a plurality of lenses 604a-604d. As shown, the seed laser assembly 314 inputs a light beam to the modular components on an integrated circuit 606 including the beam splitter 404 and the modular SiPho transceiver chip 302. The integrated circuit 606 is optically coupled via signal line 608 to provide optical input to 602d of the plurality of semiconductor optical amplifiers 602a-602d via lens 604d. The semiconductor optical amplifiers 602a-602d are coupled to transmit and receive optical signals from each other. Additionally, each of the plurality of semiconductor optical amplifiers 602a-602d is coupled via a corresponding lens 604a-604b to transmit an amplified signal back to the integrated circuit 606. Although not shown, semiconductor chip 606 also includes other inputs and outputs for providing optical signals to other components. In some embodiments, the optical ports on every two aligned chips must be at the same spacing and also need to have matched optical mode dimensions and sectional angles according to Snell's Law.

[0105] Figure 7 A cross-sectional view is shown of an example integrated chip package 700 illustrating a modular LIDAR sensor system for autonomous vehicles according to some embodiments. Figure 7 In this embodiment, an integrated chip package 700 for a LIDAR sensor system defines the configuration of optical components that provide a path for optical signals or beams to enter and exit the integrated chip package 700 and dissipate heat generated by the optical components to improve performance. The integrated chip package 700 may include a cover 704 covering the top side of the integrated chip package 700. The integrated chip package 700 may include a U-shaped block 706 coupled to the cover 704, thereby enclosing the optical components in a hermetically sealed environment. For example, the U-shaped block 706 may be made of copper. The integrated chip package 700 may include a cold plate 702 coupled to one side of the integrated chip package 700. In some embodiments, the cold plate 702 may be coupled to the cover 704 to be on top of the cover 704. In other embodiments, the cold plate 702 may be coupled to the U-shaped block 706 in a manner that does not obstruct the optical window 420 to be below the U-shaped block 706 opposite the cover 704. The material of the cold plate 702 may be one of copper, aluminum, and silicon.

[0106] The integrated chip package 700 may include a silicon photonic transceiver chip 712 separate from the MOB 708. The transceiver chip 712 is coupled to the MOB 708 via a micro-optics component 710 and is configured to receive a light beam output from the MOB 708. For example, the micro-optics component 710 may include a microlens array for collimating the light beam from the MOB 708 into a coupling section on the edge of the transceiver chip 712. The integrated chip package 700 may include components of a semiconductor optical amplifier (SOA) array chip 714. The SOA array chip 714 may be implemented as a hybrid integration coupled to a III-V semiconductor module of the transceiver chip 712 via a top surface of the transceiver chip 712. This hybrid integration is advantageous because it eliminates the need for a micro-optics component to couple the SOA array chip 714 to the transceiver chip 712. The transceiver chip 712 is configured to process the light beam received from the MOB 708. For example, transceiver chip 712 uses one or more SOA array chips 714 to amplify the beam.

[0107] The integrated chip package 700 may include an optical window 720 in a U-shaped block 706 on the bottom side opposite the cover 704 to provide an interface for optical signals. The optical window 720 may be made of glass, fused silica, or an organic polymer. The optical window 720 allows a light beam to enter and exit the surface-emitting transceiver chip 712. After the light beam is amplified using components of the SOA array chip 714 on the top surface, the transceiver chip 712 is configured to emit the light beam perpendicularly from the bottom surface through the optical window 720. For example, the light beam exits the integrated chip package 700 at a right angle to the bottom surface of the transceiver chip 712. The advantage of emitting the light beam from the surface of the transceiver chip 712 is that the configuration of the optical window 720 is easier compared to emitting from the edge of the transceiver chip 712. If the light beam is to be emitted from the edge of the transceiver chip 712, the optical window 720 may require precise alignment, whereby the optical window 720 is flush with the narrow edge of the transceiver chip 712. Therefore, the surface emission characteristics of the transceiver chip 712 simplify the assembly and manufacturability of the integrated chip package 700. The transceiver chip 712 can be configured to extend laterally over the optical window 720 to fully overlap with the optical window 720 within the integrated chip package 700. The end of the transceiver chip 712 extending laterally over the optical window 720 can be coupled to a support structure 724 for mechanical strength. In one example, the dimensions of the optical window can be millimeters in length x millimeters in width. The distance between the bottom surface of the transceiver chip 712 and the optical window 720 can be approximately X micrometers.

[0108] A light beam emitted from the integrated chip package 700 can strike a target and be reflected back into the integrated chip package 700 through the same optical window 720. A transceiver chip 712 is configured to receive and process the reflected light beam from the target. For example, the transceiver chip 712 can be configured with a photodiode to generate a photocurrent based on the reflected light beam collected through the optical window 720, and send the resulting photocurrent to a transimpedance amplifier (TIA) 722. In some embodiments, the integrated chip package 700 may include a TIA 722 integrated with the transceiver chip 712 using flip-chip bonding. The TIA 722 may be configured to convert the photocurrent into a voltage signal, which is then coupled out of the integrated chip package 700 via wire bonding 728. In some embodiments, the integrated chip package 700 may include the TIA 722 on the surface of a chip carrier outside the transceiver chip 712 and couple it to the transceiver chip 712. In other embodiments, the integrated chip package 700 excludes the TIA 722 from package integration. For example, the TIA 722 is located outside the integrated chip package 700.

[0109] In some embodiments, the integrated chip package 700 may include a configuration of dual-sided heat transfer components to dissipate heat generated by the enclosed components during operation and maintain the temperature of the enclosed components at or below a reference temperature of the cold plate 702. In the dual-sided heat transfer components, a first heat transfer component 718 may be coupled to the bottom surface of the transceiver chip 712, such that it is positioned between the transceiver chip 712 and the metal base of the U-shaped block 706 for heat dissipation. A second heat transfer component 716 may be coupled to the exposed top surface of the SOA array chip 714, such that it is positioned between the SOA array chip 714 and the cover 704 of the integrated chip package 700 for heat dissipation. For example, the heat transfer components may be thermal interface materials (e.g., aluminum nitride (AlN) ceramic, beryllium oxide ceramic, pyrolytic graphite sheet (PGS), etc.), thermoelectric coolers (TEC), liquid cooling systems, or combinations thereof. Figure 7 In this example, the first heat transfer component 718 may be a thermoelectric cooler or aluminum nitride ceramic. The second heat transfer component 716 may include a first thermal interface material layer (such as an AlN-n fixture) coupled to the exposed surface of the SOA array chip 714 and a second thermal interface material layer (such as PGS) coupled to the top of the first layer. The second heat transfer component 718 can be used at any suitable height. The second heat transfer component 718 reduces the divergence of light emitted from the bottom surface of the transceiver chip 712 through the optical window 720. The combination of the small optical window 720 and the thin height of the second heat transfer component 718 results in a large area beneath the transceiver chip 712 being covered by the second heat transfer component 718 for effective heat dissipation.

[0110] The foregoing detailed description of this disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit this disclosure to the precise forms disclosed. Many modifications and variations are possible in accordance with the foregoing teachings. The described embodiments were chosen to best explain the principles of this disclosure and its practical application, thereby enabling others skilled in the art to best utilize this disclosure in various embodiments and with various modifications suitable for the particular intended use. The scope of this disclosure is intended to be defined by the appended claims.

[0111] While some embodiments and advantages of this disclosure have been described in detail, it should be understood that various changes, substitutions, and modifications may be made herein without departing from the spirit and scope of this disclosure as defined by the appended claims. For example, those skilled in the art will readily understand that many features, functions, processes, and materials described herein can be varied while remaining within the scope of this disclosure. Furthermore, the scope of this disclosure is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, apparatuses, methods, and steps described in the specification. As will be readily understood by those skilled in the art from the description of this disclosure, processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps that are currently existing or to be developed in the future can perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, means, methods, or steps within their scope.

Claims

1. A LiDAR sensor system for light detection and ranging in vehicles, comprising: A seed laser, the seed laser being configured to output a beam; A modular modulator configured to receive the beam output from the seed laser and modulate the beam to generate a modulated beam; A modular amplifier configured to receive the modulated beam from the modular modulator and generate an amplified beam, wherein the modular amplifier includes a semiconductor optical amplifier having multiple apertures; as well as A modular transceiver chip coupled to the modular modulator and the modular amplifier, the modular transceiver chip being configured to emit the light beam perpendicularly from a first surface of the modular transceiver chip through an optical window, and to receive the reflected light beam from a target through the optical window.

2. The LIDAR sensor system according to claim 1, wherein, The seed laser includes a laser with a grating structure that provides optical feedback to output the beam.

3. The LIDAR sensor system according to claim 2, wherein, The seed laser includes a lens that couples the beam to the modular modulator, the lens having a spacing in the range of 450 micrometers to 550 micrometers.

4. The LIDAR sensor system according to claim 1, wherein, The modular modulator performs in-phase and quadrature modulation to generate the modulated beam.

5. The LIDAR sensor system according to claim 1, wherein, The modular modulator performs frequency modulation to generate the modulated beam.

6. The LIDAR sensor system according to claim 1, wherein, The modular modulator and the seed laser are integrated into a single chip.

7. The LIDAR sensor system according to claim 6, wherein, The seed laser is mounted on a first base, and the modular transceiver chip coupled to the modular modulator is mounted on a second base for aligning the height of the seed laser and the height of the modular transceiver chip for optical coupling.

8. The LIDAR sensor system according to claim 1, wherein, The modular amplifier includes a semiconductor optical amplifier, which is integrated with a U-shaped passive component for optical amplification.

9. The LIDAR sensor system according to claim 1, wherein, The modular amplifier includes a tapered semiconductor optical amplifier configured to receive the modulated beam from the modular modulator and generate the amplified beam through stimulated emission.

10. The LIDAR sensor system according to claim 1, wherein, The modular amplifier includes one of indium phosphide (InP), gallium arsenide (GaAs), indium monoarsenide (InAs), gallium nitride (GaN), indium antimonide (InSb), or rare earth doped materials.

11. The LIDAR sensor system according to claim 1, wherein, The semiconductor optical amplifier with multiple apertures has additional material on its sides for bow-shaped management.

12. The LIDAR sensor system according to claim 1, wherein, The modular amplifier includes a first bar mounted on a first portion of the modular amplifier and a second bar mounted on a second portion of the modular amplifier, the second bar having a coefficient of thermal expansion matching that of the first bar, and the first bar and the second bar being configured to reduce the junction temperature of the modular amplifier.

13. The LIDAR sensor system according to claim 1, wherein, The modular modulator is optically coupled to the modular amplifier via a lens array.

14. The LIDAR sensor system according to claim 13, wherein, The lens array compensates for the height difference between the first height of the base of the modular modulator and the second height of the base of the modular amplifier.

15. The LIDAR sensor system of claim 1, further comprising a beam splitter coupling the modular modulator to the modular amplifier, wherein, The beam splitter includes 1 to 16 beam splitters with a spacing in the range of 450 micrometers to 550 micrometers.

16. The LIDAR sensor system of claim 1, further comprising a lens array coupling the modular modulator to the modular amplifier, and a beam splitter comprising a plurality of 1 to 4 beam splitter chips having a spacing in the range of 450 to 550 micrometers, wherein, The lens array comprises four lenses with a spacing in the range of 450 to 550 micrometers.

17. The LIDAR sensor system according to claim 1, wherein, The modular modulator, the modular amplifier, and the modular transceiver chip are horizontally integrated.

18. The LIDAR sensor system according to claim 1, wherein, The modular modulator, the modular amplifier, and the modular transceiver chip are vertically integrated.

19. The LIDAR sensor system according to claim 1, wherein, The modular modulator, the modular amplifier, and the modular transceiver chip are part of the autonomous vehicle.

20. The LIDAR sensor system according to claim 1, wherein, The modular modulator, the modular amplifier, and the modular transceiver chip are part of an autonomous vehicle control system.

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