Light detection and ranging (LIDAR) system including modular components

Abstract

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

Description

Technical Field

[0001] The present disclosure generally relates to modular components for components of a light detection and ranging (LIDAR) system, and more particularly to a LIDAR system including a modular modulator, a modular amplifier, and a modular transceiver chip. Background Art

[0002] LIDAR sensor systems are used for a variety of applications from altimetry to imaging to collision avoidance. The design and implementation of LIDAR sensor systems can use a photonic integrated circuit (PIC) or an integrated optical circuit, which is a chip containing photonic components. In the past, attempts have been made to include an increasing number of photonic components of a LIDAR system on a single PIC. However, the problem with these attempts is that they are complex and significantly reduce the yield when producing such complex chips. Other prior art methods have used fiber optic connectors to couple different components of a LIDAR system. In addition to the additional space required, the problem with using fiber optic cable connectors is the configuration complexity and alignment issues of using the fiber optic and the connectors to function. Therefore, there is a need for a method of constructing a LIDAR system with high yield and reduced complexity. Summary of the Invention

[0003] Embodiments of the present disclosure relate to a modular architecture for a light detection and ranging (LIDAR) sensor system for a vehicle, and more particularly to a LIDAR sensor system including modular components and a method for configuring components for cooperation and communication. According to one aspect of the subject matter described in the present disclosure, there is provided a LIDAR sensor system including: 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 produce 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 a plurality of apertures; and a modular transceiver chip coupled to the modular modulator and the modular amplifier, the transceiver chip being configured to vertically emit a light beam through an optical window from a first surface of the transceiver chip and receive a reflected light beam from a target through the optical window.

[0004] These and other embodiments may each optionally include one or more of the following features. For example, the features may include a seed laser that includes a laser having a grating structure that provides optical feedback to output a beam, or a lens that couples the beam to a modular modulator, the lens having a pitch in the range of 450 microns to 550 microns. For example, the features may further include that the modular modulator performs in-phase and quadrature modulation or frequency modulation to generate a modulated beam. In another example, the features may include that the modular modulator and the seed laser are 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 by stimulated emission. For example, in one aspect, the modular amplifier includes one of indium phosphide (InP), gallium arsenide (GaAs), silicon nitride (SiN), indium monoarsenide (InAs), gallium nitride (GaN), or indium antimonide (InSb). The features may further include a specific semiconductor optical amplifier having additional material on its side for bow management. Additionally, the features may include that the modular amplifier includes a first strip mounted on a first part of the modular amplifier and a second strip mounted on a second part of the modular amplifier, the second strip having a coefficient of thermal expansion that matches 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 are 16 aperture strips, and the modular amplifier includes 16 tapered semiconductor optical amplifiers. For example, the features may include a modular modulator optically coupled to the modular amplifier through a lens array, or the lens array compensates for the height difference between a first height of the submount of the modular modulator and a second height of the submount of the modular amplifier. The features may further include that the modular modulator, the modular amplifier, and the modular transceiver chip are fully tested before high-volume integration. Other features may include a beam splitter that couples the modular modulator to the modular amplifier, and the beam splitter includes a 1-to-16 beam splitter having a pitch in the range of 450 to 550 microns. For example, the features may include a lens array that couples the modular modulator to the modular amplifier, and a beam splitter that includes a plurality of 1-to-4 beam splitter chips having a pitch in the range of 450 to 550 microns, and wherein the lens array includes four lenses and has a pitch in the range of 450 to 550 microns. Additionally, the features may include that the modular modulator, the modular amplifier, and the modular transceiver chip are integrated horizontally or vertically.Additionally, features can include that a modular modulator, a modular amplifier, and a modular transceiver chip are part of an autonomous vehicle or part of an autonomous vehicle control system.

[0005] According to another aspect of the subject matter described in this disclosure, there is provided a LIDAR sensor system for a vehicle. The LIDAR sensor system includes: a seed laser configured to output a light beam; a modulator coupled to the seed laser to receive the light beam from the seed laser and modulate the light beam to generate a modulated light beam; an amplifier coupled to the modulator to receive the modulated light beam from the modulator and generate an amplified light beam; and a transceiver coupled to the modulator and the amplifier. The transceiver is configured to process and emit the amplified light beam in a direction relative to the transceiver by surface emission, and receive and process a reflected light beam from an object in the environment in which the vehicle is located. In some embodiments of this disclosure, an autonomous vehicle control system can include the LIDAR sensor system described herein and one or more processors configured to use the reflected light beam to determine at least one of a range to an object or a speed of the object, and control the operation of the autonomous vehicle in response to at least one of the range or the speed. In some embodiments of this disclosure, an autonomous vehicle can include the LIDAR sensor system, a steering system, a braking system, and a vehicle controller described herein. The vehicle controller can include one or more processors configured to use the reflected light beam to determine at least one of a range to an object or a speed of the object, and 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 embodiments may each optionally include one or more of the following features. For example, the features may include a transceiver that includes an optical window through which an amplified beam is emitted and a reflected beam is received. The features may also include surface emission that includes emitting the amplified beam perpendicularly from the surface of the transceiver. For example, the features 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, the features may include that a modulator and a seed laser are integrated into a seed laser assembly, and the seed laser assembly is mounted on a first substrate and the transceiver is mounted on a second substrate for aligning the height of the seed laser and the height of the transceiver for optical coupling. In different examples, the features may include that the amplifier includes a semiconductor optical amplifier, and the semiconductor optical amplifier is integrated with a U-shaped passive component for optical amplification. In another example, the features may include an amplifier that includes a tapered semiconductor optical amplifier configured to receive a modulated beam from a modulator and generate an amplified beam by stimulated emission. In one instance, the amplifier may include at least one of indium phosphide (InP), gallium arsenide (GaAs), indium monoarsenide (InAs), gallium nitride (GaN), indium antimonide (InSb), or a rare earth doped material. For example, the features may include that the modulator is optically coupled to the amplifier through a first lens array that compensates for the height difference between the first height of the substrate of the modulator and the second height of the substrate of the amplifier, and the amplifier is optically coupled to the transceiver through 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 beam splitter that couples the output of the modulator to the input of the amplifier, and the beam splitter includes a 1 to 16 beam splitter having a pitch in the range of 450 to 550 microns. In different examples, the features may also include a first lens array that couples the output of the beam splitter to the input of the amplifier, the beam splitter includes a plurality of 1 to 4 beam splitter chips having a pitch in the range of 450 to 550 microns, and the first lens array includes four lenses and has a pitch in the range of 450 to 550 microns. Additionally, the features may include that each of the modulator, the amplifier, and the transceiver is structurally modular and horizontally aligned for optical coupling, and the optical ports on each of the modulator, the amplifier, and the transceiver are horizontally aligned for optical coupling with a matching pitch, a matching optical mode size, and a matching facet angle. In another example, the features may include that each of the modulator, the amplifier, and the transceiver is structurally modular and vertically aligned for optical coupling.

[0007] Those skilled in the art will understand that the Summary of the Invention is merely illustrative and not intended to be limiting in any way. Any feature described herein can be used in conjunction with any other feature, and any subset of these features can be used in combination according to various embodiments. Other aspects, inventive features, and advantages of the devices and / or processes described herein, which are limited only by the claims, will become apparent in the detailed description set forth herein and in connection with the accompanying drawings. Additionally, 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments are shown by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals refer to similar elements and in which:

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

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

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

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

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

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

[0015] Figure 4 is a high-level block diagram illustrating example modular components of a LIDAR sensor system for an autonomous vehicle with horizontal integration according to some embodiments.

[0016] Figure 5 is a high-level block diagram illustrating example modular components of a LIDAR sensor system for an autonomous vehicle with horizontal or vertical integration according to some embodiments.

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

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

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

[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 by microlenses. Due to this modularity, the modular LIDAR sensor system 300 overcomes the disadvantages of the prior art described above because each discrete integrated circuit has a much higher yield for each modular component. This modular design allows the efficacy of each component to be tested individually in various aspects. Additionally, this modular design also provides more configuration flexibility because different versions of any one of the modular modulator 306, the modular amplifier 304, or the modular transceiver chip 302 can be combined with other modular components. In some embodiments, the LIDAR sensor system 300 may also include an integrated chip package for the LIDAR sensor that defines a configuration of optical components for providing a path for optical signals to travel into and out of the LIDAR sensor and dissipating 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 receive a reflected light beam from a target through the optical window.

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

[0022] In addition, 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 of one element to another element, as shown in the figures. It should be understood that the relative terms are intended to cover different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is flipped, an element described as on the "lower" side of another element will be oriented on the "upper" side of the other element. Thus, depending on the specific orientation of the figure, the exemplary term "lower" can cover both the "lower" and "upper" orientations. Similarly, if the device in one of the figures is flipped, an element described as "below" or "beneath" another element will be oriented "above" the other element. Thus, the exemplary terms "below" or "beneath" can cover both the above and below orientations.

[0023] Referring to the accompanying drawings, in which like reference numerals refer to like parts throughout the several views, Figure 1A an example of a system environment 100A of an autonomous vehicle 111A in which various techniques disclosed herein may be implemented is shown. For example, vehicle 111A may include: a powertrain 102 that includes a prime mover 104 powered by an energy source 106 and capable of providing power to a driveline 108; and a control system 110 that includes a steering control 112, a powertrain control 114, and a braking control 116. Vehicle 111A may be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or cargo and capable of traveling over land, and it should be understood that the above components 102 to 116 may vary widely depending on the type of vehicle in which they 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 can include one or more electric motors and / or internal combustion engines (etc.). The energy source 106 can 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 down the vehicle 111A, and a direction or steering component suitable for controlling the trajectory of the vehicle 111A (e.g., a rack and pinion steering linkage enables one or more wheels of the vehicle 111A to pivot about a generally vertical axis to change the angle of the rotational plane of the wheels relative to the longitudinal axis of the vehicle). In some embodiments, a combination of power systems and energy sources can 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) can be used as the prime mover 104. In the case of a hydrogen fuel cell embodiment, the prime mover 104 can include one or more electric motors, and the energy source 106 can include a fuel cell system powered by hydrogen fuel.

[0025] The direction control 112 can include one or more actuators and / or sensors for controlling and receiving feedback from the direction or steering component to enable the vehicle 111A to follow a desired trajectory. The powertrain control 114 can be configured to control the output of the powertrain 102, e.g., control the output power of the prime mover 104, control the gear position of the transmission in the drivetrain 108, etc., so as to control the speed and / or direction of the vehicle 111A. The brake control 116 can be configured to control one or more brakes that slow down or stop the vehicle 111A, e.g., 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 powertrains, drivetrains, energy sources, direction controls, powertrain controls, and brake controls. Additionally, in some embodiments, some components can be combined, e.g., where the direction control of the vehicle is mainly handled by changing the output of one or more prime movers. Thus, the embodiments disclosed herein are not limited to the specific application of the techniques described herein to autonomous wheeled land vehicles.

[0027] In the illustrated embodiment, various levels of autonomous control, including full or semi-autonomous control of vehicle 111A, may be implemented in vehicle control system 120, which may include one or more processors 122 and one or more memories 124, where each processor 122 is configured to execute program code instructions 126 stored in memory 124. The processor 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), a 3D positioning sensor 138, such as a satellite navigation system, such as GPS (Global Positioning System), GLONASS (Global Naya Navigazionnaya Sputnikovaya Sistema or Global Navigation Satellite System), BeiDou Navigation Satellite System (BDS), Galileo, Compass, etc. The 3D positioning sensor 138 may be used to determine the vehicle's position on the earth using satellite signals. Sensor 130 may optionally include camera 140 and / or IMU (Inertial Measurement Unit) 142. Camera 140 may be a single-image or stereo camera and may record static and / or video images. IMU 142 may include multiple gyroscopes and accelerometers capable of detecting the linear and rotational motion of vehicle 111A in three directions. One or more encoders 144, such as wheel encoders, may be used to monitor the rotation of one or more wheels of vehicle 111A. In some embodiments, LIDAR sensor 136 may include a structure of silicon photonic devices 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 localization subsystem 152, a perception subsystem 154, a planning subsystem 156, and a control subsystem 158. The localization subsystem 152 is primarily responsible for precisely determining the position and orientation (sometimes referred to as “pose” or “pose estimation”) of vehicle 111A within its surrounding environment and typically within a certain reference frame. The perception subsystem 154 is primarily responsible for detecting, tracking, and / or identifying objects within the environment around vehicle 111A. Machine learning models according to some embodiments can be used in tracking objects. The planning subsystem 156 is primarily responsible for planning a trajectory or path for the movement of vehicle 111A over a certain time range given a desired destination and static and moving objects within the environment. Machine learning models according to some embodiments can be used in planning vehicle trajectories. The control subsystem 158 is primarily responsible for generating appropriate control signals to control the various controls in the vehicle control system 120 in order to achieve the planned trajectory of vehicle 111A. Similarly, machine learning models can be utilized to generate one or more signals to control the autonomous vehicle 111A to achieve the planned trajectory.

[0030] It will be understood that Figure 1A the set of components for the vehicle control system 120 illustrated in 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 may be used for redundancy and / or to cover different areas around the vehicle. Further, in addition to the sensors described above, there may be other types of additional sensors 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. Additionally, although subsystems 152 through 158 are illustrated as separate from the processor 122 and the memory 124, it should be understood that in some embodiments, some or all of the functions of subsystems 152 through 158 may be implemented with program code instructions 126 residing in one or more memories 124 and executed by one or more processors 122, and these subsystems 152 through 158 may, in some instances, use the same processor and / or memory for implementation. The subsystems may be implemented at least in part using various dedicated 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 circuitry, processors, sensors, and / or other components. Further, the 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 may be used as a redundant or backup control system for vehicle 111A. In some embodiments, the auxiliary vehicle control system may be capable of fully operating the autonomous vehicle 111A in the event of an adverse event in the vehicle control system 120, while in other embodiments, the auxiliary vehicle control system may only have limited functionality, e.g., 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] Generally, different architectures can be used to implement Figure 1A the various components illustrated in, and these architectures include 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 a main storage device 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 that stored on a mass storage device or another computer controller. Figure 1A One or more of the processors 122 illustrated in or a completely separate processor can be used to implement additional functions in vehicle 1A other than for autonomous control purposes, such as controlling an entertainment system, operating doors, lights, convenience features, etc.

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

[0034] Furthermore, 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, etc. Otherwise, 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) that are adapted to communicate with one or more networks 176 to permit information communication with other computers and electronic devices, including, for example, central services such as cloud services, from which vehicle 111A receives information including a trained machine learning model and other data for its autonomous control. One or more networks 176 may be, for example, communication networks and include a wide area network (“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. One or more networks 176 may optionally utilize one or more standard communication technologies, protocols, and / or interprocess communication technologies. In some embodiments, data collected by one or more sensors 130 may be uploaded via network 176 to computing system 172 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, reference Figure 2 describes the processing of autonomous vehicle data by computing system 172 according to many embodiments.

[0036] Figure 1A Each of the processors illustrated in

[0037] Typically, routines executed to implement the various embodiments described herein, whether implemented as part of an operating system or as a specific application, component, program, object, module, or sequence of instructions, or even a subset thereof, will be referred to herein as "program code". Program code typically includes one or more instructions that reside at various times in various memories and storage devices and, when read and executed by one or more processors, perform the steps required to execute the steps or elements embodying the various aspects of the present disclosure. Additionally, while the embodiments have been and will hereinafter be described in the context of fully operational computers and systems, it should be understood that the various embodiments described herein can be distributed in a variety of forms as a program product, and that the embodiments can be implemented regardless of the specific type of computer-readable medium used to actually effectuate 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-ROM, DVD, etc.).

[0039] Additionally, the various program codes described hereinafter can be identified based on the application in which the program code is implemented in its particular embodiment. However, it should be understood that any specific program nomenclature hereinafter is used for convenience only, and thus the present disclosure should not be limited to use only in any specific application identified and / or implied by such nomenclature. Further, given computer programs can be organized in any of the usually innumerable ways into routines, procedures, methods, modules, objects, etc., and the various ways in which the program functionality can be distributed among the various software layers (e.g., operating system, libraries, APIs, applications, applets, etc.) that typically reside within a typical computer, it should be understood that the present disclosure is not limited to the specific organization and distribution of program functionality described herein.

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

[0041] The truck can include a lidar system (e.g., Figure 1A the vehicle control system 120 in Figure 2in lidar systems 201, etc.). In some embodiments, the lidar system may use frequency modulation to encode an optical signal and use optics to scatter the encoded optical signal into free space. By detecting the frequency difference between the encoded optical signal and the return signal reflected from an object, a frequency-modulated (FM) lidar system can determine the position of the object and / or accurately measure the speed of the object using the Doppler effect. The FM lidar system may use continuous wave (referred to as "FMCW lidar" or "coherent FMCW lidar") or quasi-continuous wave (referred to as "FMQW lidar"). The lidar system may 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. First, in some instances, an object (e.g., a pedestrian wearing dark clothing) may have a low reflectivity as it only reflects 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 the sensor 130 in). In other instances, an object (e.g., a shiny road sign) may have a high reflectivity (e.g., higher than 10%) as it reflects a large amount of the light hitting the object back to the sensor of the FM lidar system.

[0043] Regardless of the reflectivity of the object, the FM lidar system is able to detect (e.g., classify, distinguish, discover, etc.) objects at a greater distance (e.g., 2 times) than 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 capabilities, the FM lidar system may use a sensor (e.g., Figure 1AThe sensors in (e.g., sensor 130). In some embodiments, these sensors can 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 an FM or PM lidar system within the infrared wavelength, the FM or PM lidar system can broadcast stronger light pulses or beams while meeting eye safety standards. Traditional lidar systems are generally not single-photon sensitive and / or operate only within the near-infrared wavelength, thus requiring them to limit their light output (and distance detection capabilities) for eye safety reasons.

[0045] Therefore, by detecting objects at greater distances, an FM lidar system can have more time to react to unexpected obstacles. In fact, even a few milliseconds of additional time can improve safety and comfort, especially for heavy vehicles (e.g., commercial truck vehicles) driving at highway speeds.

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

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

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

[0049] Another advantage of the FM lidar system is that it has less static interference compared to traditional lidar systems. That is, traditional lidar systems designed to be light-sensitive typically do not perform well in bright sunlight. These systems are also prone to crosstalk (e.g., when sensors are confused by each other's light pulses or beams) and self-interference (e.g., when a sensor is confused by its own previous light pulses or beams). To overcome these drawbacks, vehicles using traditional lidar systems typically require additional hardware, complex software, and / or more computing power to manage this "noise".

[0050] In contrast, the FM lidar system does not suffer from these types of problems because each sensor is specifically designed to respond only to its own light characteristics (e.g., beam, light wave, light pulse). If the returned light does not match the timing, frequency, and / or wavelength of the originally emitted light, the FM sensor can filter out (e.g., remove, ignore, etc.) that data point. Thus, the FM lidar system produces (e.g., generates, exports, etc.) more accurate data with fewer hardware or software requirements, enabling safer and smoother driving.

[0051] Finally, the FM lidar system is easier to scale than traditional lidar systems. As more and more self-driving vehicles (e.g., cars, commercial trucks, etc.) appear on the road, vehicles driven by the FM lidar system may not have to face interference problems caused by sensor crosstalk. In addition, the FM lidar system uses less optical peak power than traditional lidar sensors. Therefore, some or all of the optical components of the FM lidar can be produced on a single chip, which has its own benefits as discussed herein.

[0052] Figure 1BFIG. 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, commercial truck 180B may include a vehicle configured for long-haul freight transportation, regional freight transportation, intermodal freight transportation (i.e., where a road-based vehicle is used as one of multiple transportation modes to move cargo), and / or any other road-based freight transportation application. Commercial truck 180B may be a flatbed truck, a refrigerated truck (e.g., a freezer truck), a ventilated van (e.g., a dry van), a moving truck, etc. Cargo 182B may be merchandise and / or products. Commercial truck 180B may include a trailer for carrying cargo 182B, such as a flatbed trailer, a lowboy trailer, a step deck trailer, a telescopic flatbed trailer, a side-hanger trailer, etc.

[0053] Environment 100B includes object 111B (shown as another vehicle in Figure 1B ), which is within a distance range of equal to or less than 30 meters from the truck.

[0054] Commercial truck 180B may include a lidar system 184B (e.g., an FM lidar system, Figure 1A vehicle control system 120 in Figure 2 lidar system 201 in Figure 1B etc.), for determining the distance to object 111B and / or measuring the speed of object 111B. Although

[0055] FIG. shows one lidar system 184B mounted in front of commercial truck 180B, the number of lidar systems and the mounting area of the lidar systems on the commercial truck are not limited to a specific number or a specific area. Commercial truck 180B may include any number of lidar systems 184B (or its components, such as sensors, modulators, coherent signal generators, etc.), which are mounted on any area (e.g., front, rear, side, top, bottom, below, and / or underneath) of commercial truck 180B to facilitate the detection of objects in any free space relative to commercial truck 180B.

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

[0056] Figure 1C FIG. 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 (e.g., commercial truck 180B, cargo 182B, lidar system 184B, etc.) included in environment 100B.

[0057] Environment 100C includes object 111C (shown as another vehicle in Figure 1C ), which is within a distance range from commercial truck 180B that is (i) greater than 30 meters and (ii) equal to or less than 150 meters. As shown, the lidar system 184B in environment 100C can be configured to detect an object (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a distance (e.g., 100 meters) from commercial truck 180B.

[0058] Figure 1D 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 as included in environment 100B (e.g., commercial truck 180B, cargo 182B, lidar system 184B, etc.).

[0059] Environment 100D includes object 111D (shown as another vehicle in Figure 1D ), which is within a distance range from commercial truck 180B that is greater than 150 meters. As shown, the lidar system 184B in environment 100D can be configured to detect an object (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at a distance (e.g., 300 meters) from commercial truck 180B.

[0060] In commercial truck applications, it is important to effectively detect objects at all ranges due to the increased weight and correspondingly longer stopping distances required for such vehicles. Due to the above advantages, FM lidar systems (e.g., FMCW and / or FMQW systems) or PM lidar systems are well-suited for commercial truck applications. Thus, commercial trucks equipped with such systems can have enhanced capabilities to safely move both people and cargo over short or long distances, thereby improving not only the safety of commercial trucks but also the safety of surrounding vehicles. In various embodiments, such FM or PM lidar systems can be used in: semi-autonomous applications, where the commercial truck has a driver and some functions of the commercial truck are autonomously operated 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 a lidar system using CW modulation, the modulator continuously modulates the laser. For example, if the modulation period is 10 seconds, the input signal is modulated throughout the 10 seconds. In contrast, in a lidar system using quasi-CW modulation, the modulator modulates the laser to have both an active portion and a non-active portion. For example, for a 10-second period, the modulator modulates the laser only for 8 seconds (sometimes referred to as the "active portion") but not for 2 seconds (sometimes referred to as the "non-active portion"). By doing so, the lidar system is able to reduce the power consumption for that 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 beneficial to operate the lidar system using quasi-CW modulation, where FMCW measurement and signal processing methods are used, but the optical signal is not always on (e.g., enabled, powered on, transmitting, etc.). In some embodiments, the quasi-CW modulation can have a duty cycle equal to or greater than 1% and up to 50%. If energy can be consumed during the off state (e.g., disabled, powered off, etc.) during the actual measurement time, then there can be an improvement in the signal-to-noise ratio (SNR) and / or a reduction in the signal processing requirements to coherently integrate all the energy over a longer time scale.

[0063] Figure 2 is a block diagram showing an example environment of a lidar sensor system for an autonomous vehicle according to some embodiments. Environment 200 includes a lidar sensor system 201, and the lidar sensor system 201 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 figure), and the Rx path includes one or more Rx input / output ports ( Figure 2 not shown in the figure).

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

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

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

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

[0068] The environment 200 includes a vehicle control system 120 (e.g., Figure 1A the vehicle control system 120 in

[0069] coupled to the lidar system 201). In some embodiments, the vehicle control system 120 may be coupled to the Rx path via one or more Rx input / output ports. Figure 2 The Tx path may include a laser source 202, a modulator 204A, a modulator 204B, an amplifier 206, and one or more transmitters 216. The Rx path may include one or more receivers 222, a mixer 208, a detector 212, a transimpedance amplifier (TIA) 214, and one or more analog-to-digital converters (ADCs). Although

[0070] only a selected number of components and only one input / output channel are shown; however, the environment 200 may include any number of components and / or input / output channels (in any combination) interconnected in any arrangement to facilitate the combination of multiple functions of the lidar system to support the operation of the vehicle.

[0071] The laser source 202 may 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. Figure 2shown as “RF1”) and modulates the phase and / or frequency of the optical signal using continuous wave (CW) modulation or quasi-CW modulation 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 to optical device 210 via one or more transmitters 216. One or more transmitters 216 can include one or more optical waveguides or antennas.

[0072] Optical device 210 can be configured to direct the amplified optical signal it receives from the Tx path towards object 218 into the environment within a given field of view, can receive a return signal reflected back from object 218, and provide the return signal to mixer 208 of the Rx path via one or more receivers 222. One or more receivers 222 can include one or more optical waveguides or antennas. In some arrangements, transmitters 216 and receivers 222 can constitute one or more transceivers ( Figure 2 not shown in). In some arrangements, one or more transceivers can include monostatic transceivers or bistatic transceivers.

[0073] Laser source 202 can be configured to provide an LO signal to modulator 204B, which is configured to modulate the phase and / or frequency of the LO signal based on a second RF signal (shown as “RF2” in Figure 2 to generate a modulated LO signal and send the modulated LO signal to mixer 208 of 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 the down-converted signal and the modulated signal.

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

[0077] In some embodiments, 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 embodiments, the TIA 214 may have a gain between 4 kiloohms and 25 kiloohms.

[0078] In some embodiments, the detector 212 and / or the TIA 214 may have a 3 dB bandwidth between 80 kilohertz (kHz) and 450 megahertz (MHz).

[0079] The vehicle control system 120 may 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 therefrom via one or more ADCs 220.

[0080] In some embodiments, the modulator 204A and / or the modulator 204B may have a bandwidth between 400 megahertz (MHz) and 1000 (MHz).

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

[0082] Figure 3FIG. 0 depicts a high - level block diagram showing example components 302, 304, 306, and 308 of a modular LIDAR sensor system 300 for an autonomous vehicle according to some embodiments. 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 described above, the modular LIDAR sensor system 300 is particularly advantageous because its modular design allows each of the components 302, 304, 306, and 308 to be discrete integrated circuits optically coupled by microlenses. This provides higher yields for the modular components 302, 304, 306, and 308 as well as configurability and ease of assembly of different variants of each modular component 302, 304, 306, and 308. This modular architecture is particularly advantageous because each of the seed laser 308, the modular modulator 306, the modular amplifier 304, and the modular transceiver chip 302 can be constructed and tested individually and then assembled into the configuration that will be referred to below with reference to Figure 4 and 5 described configurations. Basically, Figure 3 、 Figure 4 and Figure 5 's modular architecture consists only of discrete integrated circuits plus microlenses. This modular architecture eliminates the need for components for any fiber - optically - coupled modular architecture.

[0083] The seed laser 308 is provided to generate a light beam. In some embodiments, the seed laser 308 can be a light source, e.g., a distributed feedback (DFB) diode laser source. The light or light beam from the seed laser 308 can be optically coupled to be input into the modular modulator 306. In some embodiments, the seed laser 308 includes a DFB diode laser source 310 and a microlens assembly 312 that couples 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] The modular modulator 306 receives the light beam generated by the seed laser and generates a modulated optical signal. In some embodiments, the modular modulator 306 includes a modulator and a beam splitter (see Figure 4 and 5 below). In some embodiments, the modular modulator 306 performs in - phase and quadrature modulation to generate a modulated light beam. In some embodiments, the modular modulator 306 performs phase modulation to generate a modulated light beam. The 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 that is a passive component integrated with the modulator of the modular modulator 306, as will be referred to below with reference to Figure 4described in more detail. In some embodiments, the beam splitter is a plurality of beam splitters, as will be described below with reference to Figure 5 described in more detail. The modular modulator 306 is modular in that it can be constructed as a single integrated circuit.

[0085] In some embodiments, the seed laser 308 and the modular modulator 306 can be integrated to form a seed laser assembly 314. In some embodiments, the seed laser assembly 314 is mounted on a first submount, and the 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] The modular amplifier 304 is one or more semiconductor optical amplifiers (SOAs). In some embodiments, the modular amplifier 304 is one or more tapered semiconductor optical amplifiers (TSOAs). In some embodiments, the 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 can be an integrated photonic device based on III-V semiconductors, where all of its components are made of III-V materials and formed / set on a single substrate made of III-V materials. Additionally, in some embodiments, each SOA array chip can include four to five channels and is configured to amplify a light beam by stimulated emission. The modular amplifier 304 is optically coupled to the modular modulator 306 through a microlens (not shown). Similarly, the modular amplifier 304 is optically coupled to provide an amplified signal to the modular transceiver chip 302 through a microlens (not shown). The details of this optical coupling will be described below with reference to Figure 4 and 5 describe the details of this optical coupling in more detail.

[0087] In some embodiments, the modular silicon photonics (SiPho) transceiver chip 302 includes at least one of a silicon photonics circuit, a programmable logic controller (PLC), or a III-V semiconductor circuit. The modular SiPho transceiver chip 302 uses the 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 through an optical window of the integrated chip package. The modular SiPho transceiver chip 302 processes the light collected from the reflection 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 of the integrated chip package.

[0088] Figure 4 is a high-level block diagram showing example modular components of a horizontally integrated LIDAR sensor system 400 for an autonomous vehicle 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 similar structures, forms, and functions as described above with reference to Figure 3 and thus will not be described again here. The modular modulator 306 is coupled to the beam splitter 404 through the 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. An example configuration of such an integration is shown in a cross-section on the left side of these components 306, 308, 402 in a Figure 4 with an upper p-type (p-up) semiconductor structure.

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

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

[0092] The TSOA array 408 has the same number of TSOAs as the output signals from the beam splitter 404. In other words, for each signal output by the beam splitter 404, there is a corresponding TSOA. In some embodiments, the beam splitter 404 outputs 16 optical signals, and the TSOA array 408 includes 16 TSOAs. In some embodiments, the beam splitter 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, where the array includes 16 TSOAs. As will be described below, the array of TSOAs includes bilateral cooling and a substrate surface (real estate) on one side for flatness. In some embodiments, the TSOAs have a pitch of 500 μm. It should be understood that in other embodiments, the array can be other types of SOAs. The TSOA array 408 is optically coupled to the beam splitter 404 through the first microlens array 406a and optically coupled to the modular SiPho transceiver chip 302 through the second microlens array 406b.

[0093] The second microlens array 406b is used to optically couple the output light of the TSOA array 408 to the modular SiPho transceiver chip 302. The second microlens array 406b includes microlenses for each signal output by the TSOA array 408. In essence, the second microlens array 406b includes microlenses for each TSOA in the TSOA array 408. In some embodiments, the second microlens array 406b includes 16 microlenses with a pitch of 500 μm. In some embodiments, the second microlens array 406b includes 32 microlenses with a pitch of 500 μm. 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 an integrated circuit. An example configuration for such an integration is shown in a cross-section to the left of these components 406a, 408, and 406b in Figure 4 and has a bottom p-type semiconductor structure.

[0095] The modular components 306, 402, 404, 406a, 408, 406b, and 302 described above are horizontally integrated, which means that each semiconductor chip forming each modular component is stacked on top of each other as shown. 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 embodiments, according to Snell's law, the optical ports on every two aligned chips must be on the same pitch and have matching optical mode sizes and facet angles.

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

[0097] By dividing the beam splitter 404 into a plurality of beam splitter chips 504a - 504b; dividing the first microlens array 406a into a plurality of microlens arrays 506a - 506d; dividing the TSOA chip 408 into a plurality of TSOA chips 508a - 508d; and dividing the second microlens array 406b into a plurality of microlens arrays 510a - 510d, the Figure 5 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. This architecture does require an increased number of vertical or horizontal alignments of the modular components 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 similar structures, forms, and functions as described above with reference to Figure 3 and Figure 4 and thus will not be described again here.

[0099] The 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 beam splitter 504a-504d. For example, microlens 502a couples the modular modulator 306 to the beam splitter 504a. Similarly, microlens 502b couples the modular modulator 306 to the beam splitter 504b; microlens 502c couples the modular modulator 3062 to the beam splitter 504c; and microlens 502d couples the modular modulator to the beam splitter 504c.

[0100] In some embodiments, each of the plurality of beam splitters 504a-504d is a beam splitter chip. For example, if it is desired to Figure 4 Similar architecture, and modular beam splitter 404 is a 1-16 beam splitter, then multiple beam splitters 504a-504d will each be a 1 to 4 beam splitter chip; therefore, Figure 5 The four beam splitter chips 504a-504d will provide Figure 4 Each of the plurality of beam splitters 504a-504d 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 It is shown how any number of beam splitter chips with smaller splitting ratios can be used in a modular manner to replace a single beam splitter chip with a larger splitting 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. Figure 4 Modular design and Figure 5In the comparison of the modular design, a single microlens array 406a is replaced by a plurality of microlens arrays 506a - 506d. For example, if a single microlens 406a includes 16 microlenses with a 500 μm pitch and a similar architecture is required, then each of the microlens arrays 506a - 506d in the plurality of microlens arrays 506a - 506d will include 4 microlenses with a 500 μm pitch. In some embodiments, the number of microlens arrays and the number of microlenses in each array respectively correspond to the number of signals generated by the beam splitter chips 504a - 504d. Each of the plurality of microlens arrays 506a - 506d is then coupled to provide a corresponding optical signal to a respective TSOA chip 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] As Figure 5 shown, each of the plurality of 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 the modular design with Figure 5 the modular design comparison, a single TSOA array 408 is replaced by a plurality of TSOA chips 508a - 508d. Compared to a single array of TSOA 408, each of the TSOA chips 508a - 508d includes 4 TSOAs. In some embodiments, the plurality of TSOA chips 508a - 508d may have 16 aperture bars or a number of individual bars, double - sided cooling, a substrate surface (real estate) 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 SOAs.

[0103] Each of the plurality of TSOA chips 508a - 508d is optically coupled to the modular SiPho transceiver chip 302 through a corresponding microlens array 510a - 510d. The second plurality of microlens arrays 510a - 510d may be similar in form and function to the first plurality of microlens arrays 506a - 506d, but couple the respective TSOA chips 508a - 508d 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 showing an exemplary plan view of modular components of a LIDAR sensor system 600 for an autonomous vehicle according to some embodiments. Figure 6 A planar embodiment and layout of the modular components of the present disclosure are 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 lines 608 to provide an optical input to 602d among the plurality of semiconductor optical amplifiers 602a - 602d via lens 604d. The semiconductor optical amplifiers 602a - 602d are coupled to send and receive optical signals to and from each other. Additionally, each of the plurality of semiconductor optical amplifiers 602a - 602d is coupled via a respective lens 604a - 604b to send the amplified signal back to the integrated circuit 606. Although not shown, the 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 on the same pitch and also need to have a matching optical mode size and facet angle according to Snell's law.

[0105] Figure 7 A cross - sectional view showing an example integrated chip package 700 of a modular LIDAR sensor system for an autonomous vehicle according to some embodiments is shown. In Figure 7 it, the integrated chip package 700 for the LIDAR sensor system defines a configuration of optical components that provides a path for optical signals or light beams to enter and exit the integrated chip package 700 and dissipates 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 an airtight seal. 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 block 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 photonics transceiver chip 712 separated from the MOB 708. The transceiver chip 712 is coupled to the MOB 708 via a micro-optical component 710 and is configured to receive the light beam output by the MOB 708. For example, the micro-optical component 710 may include a microlens array for collimating the light beam from the MOB 708 into a coupling facet 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 III-V semiconductor module coupled to the transceiver chip 412 by hybrid integration on the top surface of the transceiver chip 712. Such hybrid integration is beneficial because it does not require a micro-optical component to couple the SOA array chip 714 to the transceiver chip 712. The transceiver chip 412 is configured to process the light beam received from the MOB 708. For example, the transceiver chip 712 uses one or more SOA array chips 714 to amplify the light beam.

[0107] The integrated chip package 700 may include an optical window 720 in a U-shaped block 706 on the bottom side opposite to the lid 704 to provide an interface for optical signals. The material of the optical window 720 may be one of glass, fused silica, and organic polymers. The optical window 720 allows the light beam to enter and exit the surface-emitting transceiver chip 712. After the light beam is amplified using the components of the SOA array chip 714 on the top surface, the transceiver chip 712 is configured to vertically emit the light beam through the optical window 720 from the bottom surface. For example, the light beam is emitted out of 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, where the optical window 720 is flush with the narrow edge of the transceiver chip 712. Therefore, the surface-emitting feature of the transceiver chip 712 simplifies the assembly and manufacturability of the integrated chip package 700. The transceiver chip 712 may be configured to laterally extend a threshold offset above 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 that laterally extends above the optical window 720 may be coupled to a support structure 724 for mechanical strength. In one example, the size of the optical window may be length in millimeters x width in millimeters. The distance between the bottom surface of the transceiver chip 712 and the optical window 720 may be about X microns.

[0108] The 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. The transceiver chip 712 is configured to receive and process the reflected light beam from the target. For example, the transceiver chip 712 can configure 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 can include a TIA 722 integrated with the transceiver chip 712 using flip-chip bonding. The TIA 722 can be configured to convert the photocurrent into a voltage signal, which is then coupled out of the integrated chip package 700 through wire bonding 728. In some embodiments, the integrated chip package 700 can include a 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 the package integration. For example, the TIA 722 is located outside the integrated chip package 700.

[0109] In some embodiments, the integrated chip package 700 can include a configuration of a bilateral heat transfer component for dissipating heat generated by the enclosed components during operation and maintaining the temperature of the enclosed components at or below the reference temperature of the cold plate 702. In the bilateral heat transfer component, the first heat transfer component 718 can be coupled to the bottom surface of the transceiver chip 712 such that it is placed between the transceiver chip 712 and the metal base of the U-shaped block 706 for heat dissipation. The second heat transfer component 716 can be coupled to the exposed top surface of the SOA array chip 714 such that it is placed between the SOA array chip 714 and the cover 704 of the integrated chip package 700 for heat dissipation. For example, the heat transfer component can be a thermal interface material (such as aluminum nitride (AlN) ceramic, beryllium oxide ceramic, pyrolytic graphite sheet (PGS), etc.), a thermoelectric cooler (TEC), a liquid cooling system, or a combination thereof. In Figure 7 an example, the first heat transfer component 718 can be a thermoelectric cooler or aluminum nitride ceramic. The second heat transfer component 716 can 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 have any suitable height. The second heat transfer component 718 reduces the divergence of the 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 under the transceiver chip 712 being covered by the second heat transfer component 718 for effective heat dissipation.

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

[0111] Although some embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the present disclosure as defined by the appended claims. For example, those skilled in the art will readily understand that many of the features, functions, processes and materials described herein can be varied while remaining within the scope of the present disclosure. In addition, the scope of the present disclosure is not intended to be limited to the particular embodiments of the processes, machines, manufactures, compositions of matter, devices, methods and steps described in the specification. As will be readily understood by those of ordinary skill in the art from the description of the present disclosure, processes, machines, manufactures, compositions of matter, devices, methods or steps performing substantially the same function or achieving substantially the same result as the corresponding embodiments described herein can be utilized according to the present disclosure, whether currently existing or later to be developed. Accordingly, the appended claims are intended to cover such processes, machines, manufactures, compositions of matter, means, methods or steps within their scope.

Claims

1. A light detection and ranging (LIDAR) sensor system for a vehicle, 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, wherein the modular amplifier includes a specific semiconductor optical amplifier having a plurality of apertures; And A modular transceiver chip coupled to the modular modulator and the modular amplifier, the modular transceiver chip being configured to vertically emit the light beam through an optical window from a first surface of the modular transceiver chip and receive a 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 having a grating structure that provides optical feedback to output the light beam.

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

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

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

9. The LIDAR sensor system according to claim 1, wherein, The modular amplifier includes a tapered semiconductor optical amplifier configured to receive the modulated light beam from the modular modulator and generate the amplified light beam by 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 a rare earth doped material.

11. The LIDAR sensor system according to claim 1, wherein, The specific semiconductor optical amplifier has additional material on its side for bow management.

12. The LIDAR sensor system according to claim 1, wherein, The modular amplifier includes 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 that matches the coefficient of thermal expansion of the first strip, the first strip and the second strip 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 through a lens array.

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

15. The LIDAR sensor system according to claim 1 further includes a beam splitter that couples the modular modulator to the modular amplifier, wherein, The beam splitter includes a 1 to 16 beam splitter having a pitch in the range of 450 microns to 550 microns.

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