A light detection and ranging (LIDAR) sensor system including a seed modulation module

Abstract

A light detection and ranging (lidar) system for a vehicle can include an input optical path, a first optical path, a plurality of second optical paths, a first optical amplifier, and a plurality of second optical amplifiers. The input optical path can be configured to receive a light beam from a laser source. The first optical path and the plurality of second optical paths can branch from the input optical path, respectively. The first optical amplifier can be coupled to the first optical path and configured to output a local oscillator (LO) signal. The plurality of second optical amplifiers can be coupled to the plurality of second optical paths, respectively, one of the plurality of second optical amplifiers being selectively turned on to modulate the light beam received through the second optical path and output a modulated optical signal of the light beam.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Patent Application No. 17 / 888,364 (now U.S. Patent No. 11,619,716), filed August 15, 2022, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Lidar (Lidar) sensor systems are used in a variety of applications, from altimetry to imaging to collision avoidance. Compared to conventional microwave ranging systems, such as radio wave detection and ranging (radar), lidar provides range resolution with a finer scale using a smaller beam size. Range-based optical detection can be achieved using several different techniques, including direct ranging based on the round-trip time from the optical pulse to the object, chirped detection based on the frequency difference between the emitted chirped optical signal and the reflected signal scattered from the object, and phase-coded detection based on a series of single-frequency phase changes distinguishable from natural signals.

[0004] When applying these techniques, lidar sensor systems can include a modulator configured to receive an optical signal from a laser source and modulate it before transmitting it into the environment. Lidar sensor systems can also use time-separated I / Q processing (also known as time-domain multiplexing) to overcome hardware requirements. For example, multiple transmit (TX) channels can be time-multiplexed to share limited hardware resources (e.g., receiver (RX) hardware resources). A mechanism is needed to efficiently perform modulation and multiplexing using limited hardware resources. Summary of the Invention

[0005] Embodiments of this disclosure relate to a system and method for a light detection and ranging (lidar) sensor system, and more specifically, to a system and method for a lidar sensor system including a seed modulation module.

[0006] In some embodiments of this disclosure, a device may include an input optical path, a first optical path, a plurality of second optical paths, a first optical amplifier, a plurality of second optical amplifiers, and control circuitry. The input optical path may be configured to receive a light beam from a laser source at one end. The first optical path and the plurality of second optical paths may branch off from the other end of the input optical path, respectively. The first optical amplifier may be coupled to the first optical path. The plurality of second optical amplifiers may be coupled to the plurality of second optical paths, respectively. The control circuitry may be configured to selectively activate one of the plurality of second optical amplifiers to output a modulated optical signal of the light beam. The control circuitry may be configured to synchronously activate the first optical amplifier in conjunction with activating any one of the plurality of second optical amplifiers to output a local oscillator (LO) signal.

[0007] In some implementations of the disclosure, an autonomous vehicle control system can include one or more processors and one or more computer-readable storage media. The media can store instructions that, when executed by the one or more processors, cause the one or more processors to generate, based on a beam generated from a laser source, an optical signal that is frequency shifted relative to a local oscillator (LO) signal by a frequency offset. The one or more processors can be configured to transmit the optical signal to an environment. In response to transmitting the optical signal, the one or more processors can be configured to receive a return optical signal reflected from an object in the environment. The one or more processors can be configured to generate a digital signal based on the received signal. The one or more processors can be configured to digitally mix the digital signal based on the frequency offset to generate a sample signal. The one or more processors can be configured to determine a range to the object based on the sample signal. The one or more processors can be configured to use the range to the object to control an operation of a vehicle.

[0008] In some implementations of the disclosure, a light detection and ranging (lidar) system can include the device, a laser source configured to generate a beam, a plurality of transmit (TX) channels, and one or more optical components. The one or more optical components can be configured to receive, from the device, a first modulated optical signal and a first LO signal associated with the first modulated optical signal. The one or more optical components can be configured to receive, from the device, a second modulated optical signal and a second LO signal associated with the second modulated optical signal. The one or more optical components can be configured to transmit the first modulated optical signal and the second modulated optical signal to an environment at a first TX channel and a second TX channel, respectively, among the plurality of TX channels. The one or more optical components can be configured to receive a first return optical signal and a second return optical signal reflected from one or more objects in the environment. The one or more optical components can be configured to pair the first return optical signal and the second return optical signal with the first LO signal and the second LO signal, respectively.

[0009] In some implementations of the disclosure, a method of generating a modulated optical signal in a circuit can include receiving, by the circuit, a beam from a laser source at an input optical path of the circuit. The circuit can include the input optical path, a first optical path and a plurality of second optical paths that branch from the input optical path, respectively, a first optical amplifier coupled to the first optical path, and a plurality of second optical amplifiers coupled to the plurality of second optical paths, respectively. The method can include receiving, by the circuit, the beam from the laser source at the input optical path. The method can include selectively turning on, by the circuit, one of the plurality of second optical amplifiers to output a modulated optical signal of the beam. The method can include turning on, by the circuit, the first optical amplifier in synchronization with turning on any of the plurality of second optical amplifiers to output a local oscillator (LO) signal.

[0010] In some implementations of the disclosure, a light detection and ranging (lidar) system for a vehicle can include an input optical path configured to receive a beam from a laser source, a first optical path and a plurality of second optical paths that branch from the input optical path, respectively, a first optical amplifier coupled to the first optical path and configured to output a local oscillator (LO) signal, and a plurality of second optical amplifiers coupled to the plurality of second optical paths, respectively. One of the plurality of second optical amplifiers can be selectively turned on to modulate the beam received through the second optical path and output a modulated optical signal of the beam.

[0011] In some implementations of the disclosure, an autonomous vehicle can include a light detection and ranging (lidar) system, at least one of a steering system or a braking system, and a vehicle controller including one or more processors. The lidar system can include an input optical path configured to receive a beam from a laser source, a first optical path and a plurality of second optical paths that branch from the input optical path, respectively, a first optical amplifier coupled to the first optical path and configured to output a local oscillator (LO) signal, and a plurality of second optical amplifiers coupled to the plurality of second optical paths, respectively. One of the plurality of second optical amplifiers can be selectively turned on to modulate the beam received through the second optical path and output a modulated optical signal of the beam. The one or more processors can be configured to operate the lidar system to emit the modulated optical signal to an environment, receive a return optical signal reflected from an object in the environment, pair the return optical signal with the LO signal to generate an electrical signal, and control at least one of the steering system or the braking system using the electrical signal. BRIEF DESCRIPTION OF DRAWINGS

[0012] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0013] These and other aspects and features of the present embodiments will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying drawings, in which:

[0014] FIG. 1A is a block diagram illustrating an example of a system environment for an autonomous vehicle, in accordance with some embodiments.

[0015] FIG. 1B is a block diagram illustrating an example of a system environment for an autonomous commercial truck, in accordance with some embodiments.

[0016] FIG. 1C is a block diagram illustrating an example of a system environment for an autonomous commercial truck, in accordance with some embodiments.

[0017] FIG. 1D is a block diagram illustrating an example of a system environment for an autonomous commercial truck, in accordance with some embodiments.

[0018] FIG. 2 is a block diagram illustrating an example of a lidar system for an autonomous vehicle, in accordance with some embodiments.

[0019] FIG. 3A is a block diagram illustrating an example of a lidar system, in accordance with some embodiments.

[0020] FIG. 3B is a block diagram illustrating an example of a seed modulation device, in accordance with some embodiments.

[0021] FIG. 3C is a block diagram illustrating an example of a seed modulation assembly, in accordance with some embodiments.

[0022] FIG. 4 is a block diagram illustrating another example of a lidar system, in accordance with some embodiments.

[0023] FIG. 5 is a flow diagram illustrating an example method for generating a modulated optical signal using a seed modulation device, in accordance with some embodiments.

[0024] FIG. 6 is a flow diagram illustrating an example method for controlling a lidar system using a seed modulation device, in accordance with some embodiments.

[0025] FIG. 7 is a block diagram illustrating an example of a computing system, in accordance with some embodiments. DETAILED DESCRIPTION

[0026] According to certain aspects, implementations in the present disclosure relate to systems and methods for controlling a vehicle using light detection and ranging (lidar), and more particularly, to systems and methods for a lidar sensor system including a seed modulation module.

[0027] According to certain aspects, an apparatus can include an input optical path, a first optical path, a plurality of second optical paths, a first optical amplifier, a plurality of second optical amplifiers, and a control circuit. The input optical path can be configured to receive a beam of light from a laser source at one end thereof. The first optical path and the plurality of second optical paths can branch from another end of the input optical path, respectively. The first optical amplifier can be coupled to the first optical path. The plurality of second optical amplifiers can be coupled to the plurality of second optical paths, respectively. The control circuit can be configured to selectively turn on one of the plurality of second optical amplifiers to output a modulated optical signal of the beam of light. The control circuit can be configured to turn on the first optical amplifier in synchronization with turning on any of the plurality of second optical amplifiers to output a local oscillator (LO) signal.

[0028] 1. System environment for autonomous vehicles

[0029] FIG. 1A is a block diagram illustrating an example of a system environment of an autonomous vehicle according to some implementations.

[0030] With reference to FIG. 1A An example autonomous vehicle 110A in which various techniques disclosed herein can be implemented can be provided. For example, the vehicle 110A can include a powertrain system 192 including a prime mover 194 driven by an energy source 196 and capable of providing power to a drivetrain 198, and a control system 180 including a directional control 182, a powertrain control 184, and a braking control 186. The vehicle 110A can be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or cargo, and vehicles capable of traveling in various environments, and it should be appreciated that the aforementioned components 180-198 can vary greatly based on the type of vehicle in which they are used.

[0031] For simplicity, the embodiments discussed below will focus on wheeled land vehicles, such as cars, vans, trucks, buses, etc. In such embodiments, the prime mover 194 can include one or more electric motors and / or internal combustion engines (etc.). The energy source 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 198 can include: wheels and / or tires and a transmission and / or any other mechanical drive components to convert the output of the prime mover 194 into vehicle motion; and one or more brakes configured to controllably stop or slow the vehicle 110A; and a direction or steering assembly suitable for controlling the trajectory of the vehicle 110A (e.g., a rack-and-pinion steering linkage enabling one or more wheels of the vehicle 110A to pivot about a generally vertical axis to change the angle of the plane of rotation of the wheel relative to the longitudinal axis of the vehicle). In some embodiments, a combination of powertrain and energy source can be used (e.g., in the case of an electric / gas hybrid vehicle), and in some instances multiple electric motors can be used (e.g., dedicated to individual wheels or axles) as the prime mover.

[0032] The direction control 182 can include one or more actuators and / or sensors for controlling and receiving feedback from the direction or steering assembly to enable the vehicle 110A to follow a desired trajectory. The powertrain control 184 can be configured to control the output of the powertrain 102, e.g., to control the output power of the prime mover 194, to control the gear of a transmission in the drivetrain 198, etc., thereby controlling the speed and / or direction of the vehicle 110A. The brake control 116 can be configured to control one or more brakes of the vehicle 110A, e.g., disc or drum brakes coupled to the wheels of the vehicle, to slow or stop the vehicle 110A.

[0033] Other vehicle types, including but not limited to off-road vehicles, all-terrain or tracked vehicles, construction equipment, etc., will necessarily use different powertrains, drivetrains, energy sources, direction controls, powertrain controls, and brake controls. Moreover, in some embodiments, some components can be combined, e.g., the direction control of the vehicle is primarily handled by changing the output of one or more prime movers. Thus, the embodiments disclosed herein are not limited to the particular application of the technology described herein in autonomous wheeled land vehicles.

[0034] Various levels of autonomous control of vehicle 110A can be implemented in vehicle control system 120, which can 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 processors can include, for example, one or more graphics processing units (“one or more GPUs”) and / or one or more central processing units (“one or more CPUs”).

[0035] Sensors 130 can include various sensors suitable for collecting information from the vehicle’s surroundings for use in controlling vehicle operations. For example, sensors 130 can include radar sensors 134, lidar (light detection and ranging) sensors 136, 3D positioning sensors 138, such as any of an accelerometer, a gyroscope, a magnetometer, or a satellite navigation system (such as GPS (Global Positioning System), GLONASS (Globalnaya Navigazionnaya Sputnikovaya Sistema or Global Navigation Satellite System), BeiDou Navigation Satellite System (BDS), Galileo, compass, etc.). 3D positioning sensors 138 can be used to determine the vehicle’s position on Earth using satellite signals. Sensors 130 can include cameras 140 and / or IMUs (inertial measurement units) 142. Cameras 140 can be single or stereo cameras and can record still and / or video images. IMUs 142 can include multiple gyroscopes and accelerometers capable of detecting linear and rotational motion of the vehicle in three directions. One or more encoders (not shown), such as wheel encoders, can be used to monitor the rotation of one or more wheels of vehicle 110A. Each sensor 130 can output sensor data at various data rates, which can be different from the data rates of other sensors 130.

[0036] The output of sensor 130 can be provided to a set of control subsystems 150, including a positioning subsystem 152, a planning subsystem 156, a perception subsystem 154, and a control subsystem 158. Positioning subsystem 152 can perform functions such as accurately determining the position and orientation (sometimes referred to as "pose") of vehicle 110A within its surrounding environment and typically within a reference frame. As part of generating labeled autonomous vehicle data, the autonomous vehicle's position can be compared to the position of another vehicle in the same environment. Perception subsystem 154 can perform functions such as detecting, tracking, identifying, and / or recognizing objects within the environment surrounding vehicle 110A. Machine learning models can be used for object tracking. Planning subsystem 156 can perform functions such as planning a trajectory for vehicle 110A over a time period given a desired destination and static and moving objects within the environment. Machine learning can be used to plan the vehicle trajectory. Control subsystem 158 can perform functions such as generating appropriate control signals to control various controls in vehicle control system 120 to achieve the planned trajectory of vehicle 110A. Machine learning models can be used to generate one or more signals to control the autonomous vehicle to implement the planned trajectory.

[0037] It should be understood that FIG. 1A The assembly of components of the vehicle control system 120 shown is merely exemplary in nature. In some embodiments, individual sensors may be omitted. Additionally or alternatively, in some embodiments, [the following may be used] FIG. 1A Multiple sensors of the type shown are used to achieve redundancy and / or coverage of different areas around the vehicle, and other types of sensors can be used. Similarly, different types and / or combinations of control subsystems can be used in other embodiments. Furthermore, although subsystems 152–158 are shown as separate from processor 122 and memory 124, it will be understood that in some embodiments, some or all of the functionality of subsystems 152–158 can be implemented by program code instructions 126 residing in one or more memories 124 and executed by one or more processors 122, and these subsystems 152–158 may be implemented using the same processor and / or memory in some instances. Subsystems can be implemented, at least in part, using various application-specific circuit logics, various processors, various field-programmable gate arrays (“FPGAs”), various application-specific integrated circuits (“ASICs”), various real-time controllers, etc., and as mentioned above, multiple subsystems can utilize circuits, processors, sensors, and / or other components. Furthermore, the various components in the vehicle control system 120 can be networked in various ways.

[0038] In some embodiments, vehicle 110A may further include an auxiliary vehicle control system (not shown), which may serve as a redundancy or backup control system for vehicle 110A. The auxiliary vehicle control system may be capable of fully operating the autonomous vehicle 110A in the event of an adverse event detected in 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 110A in response to an adverse event detected in primary vehicle control system 120. In other embodiments, the auxiliary vehicle control system may be omitted.

[0039] Typically, countless different architectures (including various combinations of software, hardware, circuit logic, sensors, networks, etc.) can be used to implement this. FIG. 1A The various components shown are illustrated. For example, each processor can be implemented as a microprocessor, and each memory can represent a random access memory (“RAM”) device, which includes: main memory; and any supplementary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable memory or flash memory), read-only memory, etc. Furthermore, each memory can be considered to include: memory storage physically located elsewhere in the vehicle 110A, 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. FIG. 1A One or more processors, or completely separate processors, shown in the diagram, can be used in the vehicle 110A to implement additional functions beyond autonomous control purposes, such as controlling the entertainment system, operating doors, lights, convenience features, etc.

[0040] In addition, to enable additional storage, the vehicle 110A may include one or more high-capacity 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.

[0041] In addition, vehicle 110A may include user interface 164 to enable vehicle 110A to receive and generate outputs from a 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).

[0042] Further, the vehicle 110A can include one or more network interfaces, e.g., network interface 162, adapted to communicate with one or more networks 170 (e.g., local area networks (“LANs”), wide area networks (“WANs”), wireless networks, and / or the Internet, etc.) to allow communication of information with other computers and electronic devices, including, for example, central services, such as cloud services, from which the vehicle 110A receives environmental and other data for its autonomous control. Data collected by the one or more sensors 130 can be uploaded to a computing system 172 via the network 170 for additional processing. A timestamp can be added to each instance of vehicle data prior to upload. Reference is made to FIG. 2 Additional processing of autonomous vehicle data by the computing system 172 according to many implementations is described.

[0043] FIG. 1A Each processor shown in FIG. 1 and various additional controllers and subsystems disclosed herein generally operate under the control of an operating system and execute or otherwise rely upon various computer software applications, components, programs, objects, modules, data structures, etc., as will be more fully described below. Furthermore, various applications, components, programs, objects, modules, etc. can also execute on one or more processors in other computers coupled to the vehicle 110A via the network 170, e.g., in a distributed, cloud-based or client-server computing environment, such that the processing required to implement the functions of the computer programs can be allocated to multiple computers and / or services on the network.

[0044] Generally, the routines executed to implement the various implementations described herein, whether implemented as part of an operating system or a specific application, component, program, object, module, or sequence of instructions or even subsets thereof, are referred to herein as “program code.” The program code can include one or more instructions stored in various memories and storage devices and, when read and executed by one or more processors, can implement the steps or elements necessary to execute the steps embodied by the various aspects of the present disclosure. Moreover, while the implementations have and will be described in the context of fully functioning computers and systems, those skilled in the art will appreciate that the various implementations described herein are capable of being distributed as program products in a variety of forms, and that the implementations described herein apply equally regardless of the particular type of computer readable media used to actually carry out the distribution.

[0045] 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 drives, magnetic tape, and optical disks (e.g., CD-ROMs, DVDs, etc.), among others.

[0046] Furthermore, the various program codes described below can be identified based on the application in which they are implemented in a particular implementation. However, it should be understood that any particular program nomenclature described 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 typically endless ways in which computer programs can be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functionality can be distributed across various software layers residing within a typical computer (e.g., operating systems, libraries, APIs, applications, applets, etc.), it should be understood that this disclosure is not limited to the specific organization and distribution of program functionality described herein.

[0047] FIG. 1A The environments shown 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.

[0048] 2. FM LIDAR for automotive applications

[0049] Trucks may include lidar systems (e.g., FIG. 1A The vehicle control system 120 in FIG. 2 The lidar system in China 201 FIG. 3A The lidar system 301 in FIG. 4 (e.g., lidar system 401). In some embodiments, the 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, the frequency modulation (FM) lidar system can determine the position of the object and / or accurately measure the velocity of the object using the Doppler effect. The FM lidar system can use continuous wave (referred to as "FMCW lidar" or "coherent FMCW lidar") or quasi-continuous wave (referred to as "FMQW lidar"). The lidar system can use phase modulation (PM) to encode the optical signal and use optics to scatter the encoded optical signal into free space.

[0050] FM or phase-modulated (PM) lidar systems can offer significant advantages over conventional lidar systems in automotive and / or commercial truck applications. Firstly, in some instances, objects (e.g., pedestrians wearing dark clothing) may have low reflectivity, as they reflect only a small amount of light (e.g., 10% or less) back to the sensors of the FM or PM lidar system. FIG. 1Aobjects (e.g., a shiny road sign) can have a high reflectivity (e.g., above 10%) because it reflects a large amount of light that hits the object back to the sensors of the FM lidar system.

[0051] Regardless of the reflectivity of the object, the FM lidar system is able to detect (e.g., classify, recognize, find, etc.) the object at a much farther distance (e.g., 2x) than a conventional lidar system. For example, the FM lidar system can detect a low reflectivity object 300 meters away, and a high reflectivity object 400 meters away.

[0052] To achieve such improvements in detection capabilities, the FM lidar system can use sensors (e.g., FIG. 1A In some implementations, these sensors can be single-photon sensitive, meaning that they can detect the smallest possible amount of light. While the FM lidar system can use infrared wavelengths (e.g., 950 nm, 1550 nm, etc.) in certain applications, it is not limited to the infrared wavelength range (e.g., near infrared: 800 nm - 1500 nm; mid infrared: 1500 nm - 5600 nm; and far infrared: 5600 nm - 1,000,000 nm). By operating the FM or PM lidar system at infrared wavelengths, the FM or PM lidar system can broadcast stronger pulses or beams of light while meeting eye safety standards. Conventional lidar systems are typically not single-photon sensitive and / or only operate at near infrared wavelengths, necessitating that they limit their light output (and distance detection capabilities) for eye safety reasons.

[0053] Thus, by detecting objects at a farther distance, the FM lidar system can have more time to react to unexpected obstacles. In fact, even an extra few milliseconds can improve safety and comfort, especially for heavy vehicles (e.g., commercial trucks) traveling at highway speeds.

[0054] Another advantage of FM lidar systems is that it provides accurate velocity instantaneously for each data point. In some implementations, the velocity measurement is achieved 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 by a situation on a roadway where the velocity is less than 100 meters / second (m / s), this shift in wavelength of 1550 nanometers (nm) equates to a frequency shift of less than 130 megahertz (MHz). This frequency shift is small, making it 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, making it possible to use various signal processing techniques to calculate the frequency shift. This enables autonomous vehicle control systems to process incoming data more quickly.

[0055] 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 move over time. For example, a FM lidar sensor (e.g., sensor 130 in FIG. 1) can only receive a few returns (e.g., hits) of an object 300 meters away, but if these returns give a velocity value of interest (e.g., moving towards the vehicle at >70 mph), the FM lidar system and / or autonomous vehicle control system can determine a corresponding weight for the probability associated with the object. FIG. 1A

[0056] Faster recognition and / or tracking by FM lidar systems gives autonomous vehicle control systems more time to maneuver the vehicle. Better understanding of the velocity at which objects move also enables autonomous vehicle control systems to plan better reactions.

[0057] Another advantage of FM lidar systems is that it has less static electricity compared to conventional lidar systems. That is, conventional lidar systems designed to be more sensitive to light typically perform poorly in bright sunlight. These systems are also susceptible to cross-talk (e.g., when a sensor is confused by the light pulses or beams of each other) and self-interference (e.g., when a sensor is confused by its own previous light pulses or beams). To overcome these shortcomings, vehicles using conventional lidar systems often need additional hardware, complex software, and / or more computing power to manage this “noise.”

[0058] ​In contrast, FM lidar systems do not encounter these types of issues because each sensor is specifically designed to respond only to its own light characteristics (e.g., light beams, light waves, light pulses). If the returned light does not match the timing, frequency, and / or wavelength of the light that was originally emitted, the FM sensor can filter (e.g., remove, ignore, etc.) that data point. As a result, FM lidar systems produce (e.g., generate, derive, etc.) more accurate data with fewer hardware or software requirements, enabling safer, smoother driving.

[0059] Finally, FM lidar systems can be more easily scalable compared to conventional lidar systems. As more and more autonomous vehicles (e.g., cars, commercial trucks, etc.) appear on the road, vehicles powered by FM lidar systems can not have to contend with interference issues caused by sensor cross-talk. In addition, FM lidar systems use less peak power of light than conventional lidar sensors. As a result, some or all of the optical components of FM lidar can be produced on a single chip, which creates its own benefits, as discussed herein.

[0060] 3. Commercial trucking

[0061] FIG. 1B is a block diagram illustrating an example of a system environment of an autonomous commercial truck, according to some embodiments. Environment 100B includes a commercial truck 102B for hauling cargo 106B. In some embodiments, commercial truck 102B can include a vehicle configured for long-haul freight, regional freight, intermodal freight (i.e., where a road-based vehicle is used as one of multiple modes of transportation to move cargo), and / or any other road-based freight application. Commercial truck 102B can be a flatbed truck, a refrigerated truck (e.g., a refrigerated trailer), a ventilated van (e.g., a dry van), a mobile truck, etc. Cargo 106B can be goods and / or produce. Commercial truck 102B can include a trailer for carrying cargo 106B, such as a flatbed trailer, a lowboy trailer, a step deck trailer, an extendable flatbed trailer, a side-suit trailer, etc.

[0062] Environment 100B includes an object 110B (shown in FIG. 1B as another vehicle) that is within a distance range of 30 meters or less from truck.

[0063] Commercial truck 102B can include a lidar system 104B (e.g., an FM lidar system, FIG. 1A vehicle control system 120 in FIG. 2 lidar system 201 in FIG. 3A lidar system 301 in FIG. 4lidar system 401, etc.) for determining distances to objects 110B and / or measuring velocities of objects 110B. Although FIG. 1B One lidar system 104B is shown mounted on the front of the commercial truck 102B, but the number of lidar systems and the mounting area of the lidar systems on the commercial truck is not limited to a particular number or a particular area. The commercial truck 102B can include any number of lidar systems 104B (or components thereof, such as sensors, modulators, coherent signal generators, etc.) mounted on any area (e.g., front, back, side, top, bottom, under, and / or bottom) of the commercial truck 102B to facilitate detection of objects in any free space relative to the commercial truck 102B.

[0064] As shown, the lidar system 104B in the environment 100B can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) at a close distance (e.g., 30 meters or less) from the commercial truck 102B.

[0065] FIG. 1C is a block diagram illustrating an example of a system environment for an autonomous commercial truck, in accordance with some embodiments. The environment 100C includes the same components included in the environment 100B (e.g., the commercial truck 102B, the cargo 106B, the lidar system 104B, etc.).

[0066] The environment 100C includes an object 110C (shown in FIG. 1C as another vehicle) located at a distance range from the commercial truck 102B that is (i) greater than 30 meters and (ii) equal to or less than 150 meters. As shown, the lidar system 104B in the environment 100C can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) at a distance (e.g., 100 meters) from the commercial truck 102B.

[0067] FIG. 1D is a block diagram illustrating an example of a system environment for an autonomous commercial truck, in accordance with some embodiments. The environment 100D includes the same components included in the environment 100B (e.g., the commercial truck 102B, the cargo 106B, the lidar system 104B, etc.).

[0068] The environment 100D includes an object 110D (shown in FIG. 1D as another vehicle) located at a distance range from the commercial truck 102B that is greater than 150 meters. As shown, the lidar system 104B in the environment 100D can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) at a distance (e.g., 300 meters) from the commercial truck 102B.

[0069] In commercial trucking applications, it is important to effectively detect objects at all ranges due to the added weight and, thus, the longer stopping distances required for such vehicles. FM lidar systems (e.g., FMCW and / or FMQW systems) or PM lidar systems are well suited for commercial trucking applications due to the aforementioned advantages. Thus, a commercial truck equipped with such a system can have the ability to safely transport both people and cargo 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 semi-autonomous applications (where the commercial truck has a driver and certain functions of the commercial truck are automatically operated using the FM or PM lidar system) or fully autonomous applications (where the commercial truck is completely operated by the FM or lidar system alone or in combination with other vehicle systems).

[0070] 4. Continuous wave modulation and quasi-continuous wave modulation

[0071] In lidar systems that use CW modulation, the modulator continuously modulates the laser. For example, if the modulation period is 10 seconds, the input signal is modulated throughout the entire 10 seconds. Instead, in lidar systems that use quasi-CW modulation, the modulator modulates the laser with active and inactive portions. For example, for a 10 second period, the modulator modulates the laser for only 8 seconds (sometimes referred to as the “active portion”), but does not modulate the laser for 2 seconds (sometimes referred to as the “inactive portion”). By doing so, the lidar system can be able to reduce the power consumption for 2 seconds, as the modulator does not have to provide a continuous signal.

[0072] In frequency-modulated continuous wave (FMCW) lidar for automotive applications, it can be beneficial to operate the lidar system using quasi-CW modulation, where the FMCW measurement and signal processing methods are used, but the optical signal is not always in the on state (e.g., enabled, powered, transmitting, etc.). In some implementations, the quasi-CW modulation can have a duty cycle equal to or greater than 1% and up to 50%. If energy in the off state (e.g., disabled, powered down, etc.) can be consumed during the actual measurement time, then the signal-to-noise ratio (SNR) can be improved and / or the signal processing requirements can be reduced to coherently integrate all the energy over a longer time scale.

[0073] 5. LIDAR system for autonomous vehicles

[0074] FIG. 2is a block diagram illustrating an example environment for a lidar system for an autonomous vehicle, in accordance with some embodiments. Environment 200 includes lidar system 201, which includes a transmit (Tx) path and a receive (Rx) path. The Tx path includes one or more Tx input / output ports (not shown in FIG. 2 ), and the Rx path includes one or more Rx input / output ports (not shown in FIG. 2 ).

[0075] 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 photonic circuit, a photonic lightwave circuit (PLC), or a III-V semiconductor circuit.

[0076] In some embodiments, the first semiconductor substrate and / or first semiconductor package can include the Tx path, and the second semiconductor substrate and / or second semiconductor package can include the Rx path. In some arrangements, the Rx input / output ports and / or Tx input / output ports can occur (or be formed / arranged / positioned / placed) along one or more edges of the one or more semiconductor substrates and / or semiconductor packages.

[0077] Environment 200 includes one or more optical devices 210 (e.g., an oscillating scanner, a unidirectional scanner, a Risley prism, a circulator optical device, and / or a beam collimator, etc.) coupled to lidar system 201. In some embodiments, the one or more optical devices 210 can be coupled to the Tx path via the one or more Tx input / output ports. In some embodiments, the one or more optical devices 210 can be coupled to the Rx path via the one or more Rx input / output ports.

[0078] Environment 200 includes vehicle control system 120 (e.g., vehicle control system 120 in FIG. 1) coupled to lidar system 201. In some embodiments, vehicle control system 120 can be coupled to the Rx path via the one or more Rx input / output ports.

[0079] The Tx path can include laser source 202, modulator 204A, modulator 204B, and amplifier 206. The Rx path can include mixer 208, detector 212, and transimpedance amplifier (TIA) 214. Although FIG. 2 only a select number of components and only one input / output channel are shown; environment 200 can include any number of components and / or input / output channels (in any combination) interconnected in any arrangement to facilitate a variety of functions of the combined lidar system to support operation of the vehicle.

[0080] The laser source 202 can be configured to generate an optical signal (or beam) that is derived from (or associated with) a local oscillator (LO) signal. In some implementations, the optical signal can have an operating wavelength that is equal to or substantially equal to 1550 nanometers. In some implementations, the optical signal can have an operating wavelength that is between 1250 nanometers and 1400 nanometers.

[0081] The laser source 202 can be configured to provide the optical signal to a modulator 204A that is configured to modulate a phase and / or a frequency of the optical signal based on a first radio frequency (RF) signal (shown as "RF1" in FIG. 2

[0082] The optical device 210 can be configured to divert the amplified optical signal it receives from the Tx path into the environment within a given field of view toward an object 218, can receive a return signal that is reflected back from the object 218, and provide the return signal to the mixer 208 of the Rx path.

[0083] The laser source 202 can be configured to provide the LO signal to a modulator 204B that is configured to modulate a phase and / or a frequency of the LO signal based on a second RF signal (shown as "RF2" in FIG. 2

[0084] The mixer 208 can be configured to mix (e.g., combine, multiply, etc.) the modulated LO signal with the return signal to generate a downconverted signal and send the downconverted signal to the detector 212. In some arrangements, the mixer 208 can be configured to send the modulated LO signal to the detector 212.

[0085] The detector 212 can be configured to generate an electrical signal based on the downconverted signal and send the electrical signal to the TIA 214. In some arrangements, the detector 212 can be configured to generate the electrical signal based on the downconverted signal and the modulated signal.

[0086] The TIA 214 can be configured to amplify the electrical signal and send the amplified electrical signal to the vehicle control system 120.

[0087] ​​In some implementations, the TIA 214 can have a peak noise equivalent power (NEP) of less than 5 pico-Watts per square root Hertz (i.e., 5 x 10-12 Watts per square root Hertz). In some implementations, the TIA 214 can have a gain between 4 kilo-Ohms and 25 kilo-Ohms.

[0088] In some implementations, the detector 212 and / or the TIA 214 can have a 3 decibel bandwidth between 80 kilo-Hertz (kHz) and 450 mega-Hertz (MHz).

[0089] The vehicle control system 120 can be configured to determine a distance to the object 218 and / or measure a speed of the object 218 based on one or more electrical signals it receives from the TIA.

[0090] In some implementations, the modulator 204A and / or the modulator 204B can have a bandwidth between 400 mega-Hertz (MHz) and 1000 (MHz).

[0091] In some implementations, the modulator 204A can be configured to transmit the first modulated optical signal and the second modulated optical signal to the amplifier 206. The amplifier 206 can be configured to amplify the first modulated optical signal and the second modulated optical signal to generate an amplified optical signal to the optics 210. The optics 210 can be configured to steer the first modulated optical signal and the second modulated optical signal it receives from the Tx path into the environment within a given field of view towards the object 218, can receive corresponding first return signal and second return signal reflected back from the object 218, and provide the first return signal and the second return signal to the mixer 208 of the Rx path. The modulator 204B can 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 transmit the first modulated LO signal and the second modulated LO signal to the mixer 208 of the Rx path. The mixer 208 can be configured to pair (e.g., associate, link, identify, etc.) the first return optical signal with the first modulated LO signal and mix (e.g., combine, multiply, etc.) the first return optical signal with the first modulated LO signal to generate a first down-converted signal and transmit the first down-converted signal to the detector 212. Similarly, the mixer 208 can be configured to pair the second return optical signal with the second modulated LO signal and mix the second return optical signal with the second modulated LO signal to generate a second down-converted signal and transmit the second down-converted signal to the detector 212. The detector 212 can be configured to generate a first electrical signal and a second electrical signal based on the first down-converted signal and the second down-converted signal, respectively. The vehicle control system 120 can be configured to determine a distance to the object 218 and / or measure a speed of the object 218 based on the first electrical signal and the second electrical signal received through the TIA 214.

[0092] 6. LIDAR system including a seed modulation module

[0093] A lidar sensor system can include a modulator (e.g., a Mach-Zehnder modulator) configured to receive an optical signal from a laser source and modulate the optical signal before transmitting the optical signal to an environment. The lidar sensor system can also use time multiplexing to overcome hardware requirements. For example, multiple transmit (TX) channels can be time multiplexed to share limited hardware resources (e.g., an analog-to-digital converter (ADC)). Similarly, multiple local oscillator (LO) channels can be time multiplexed to share limited hardware resources (e.g., an optical receiver / detector). In some cases, time multiplexing can be performed by an optical switch or an electro-optical switch. Since photonic integrated circuits (PICs) are widely used today to save costs, there is a need for a PIC module / device to efficiently perform modulation and multiplexing.

[0094] To address these issues, in some embodiments, a lidar sensor system (e.g., a FMCW or other coherent lidar sensor system) can include a seed modulation device (or seed modulation module) configured to perform both modulation and multiplexing simultaneously. In some embodiments, the seed modulation device can include one or more optical amplifiers (e.g., a semiconductor optical amplifier (SOA), an erbium-doped fiber amplifier (EDFA), a fiber Raman amplifier (FRA)) for time sequencing of the amplifiers to time multiplex multiple transmit (TX) optical signals. In some embodiments, the seed modulation device can perform amplitude modulation (AM) or phase modulation using one or more SOAs. For example, the seed modulator device can generate a modulated optical signal that is in a range of -20 dbm to 0 dbm relative to an original input optical signal. The seed modulation device can forward bias or reverse bias the SOA depending on a time sequence controlled by a control circuit.

[0095] In some embodiments, the seed modulation device can include an input leg (or input optical leg), a first leg (or first optical leg) branching from the input optical leg at one end thereof, and a second leg (or second optical leg) branching from the input optical leg at one end thereof. In some embodiments, the input optical leg can be formed / arranged / positioned between the first optical leg and the second optical leg. The seed modulation device can receive an optical beam (or optical signal) at the input optical leg. In some embodiments, the device can receive the optical signal from a laser source at the input optical leg. The first optical leg can be used as a local oscillator (LO) path, while the second optical leg can be used as a TX path. The device can include multiple TX paths branching from the second optical leg at one end thereof. In some embodiments, the device can include a laser source therein.

[0096] In some implementations, the seed modulation device can include an input port coupled to the input optical path and configured to receive the optical signal from the laser source. The device can include an LO output port coupled / connected to another end of the first optical path, and a plurality of TX output ports coupled / connected to other ends of the plurality of TX paths, respectively.

[0097] In some implementations, the seed modulation device can include one or more first optical amplifiers coupled to the first optical path. The one or more first optical amplifiers can include SOAs. In some implementations, the device can include a plurality of first phase modulators coupled to the first optical path. The plurality of first phase modulators can include electro-optical modulators or liquid crystal modulators. The one or more first optical amplifiers can be formed / positioned / set between the plurality of first phase modulators and the LO output port.

[0098] In some implementations, the seed modulation device can include a plurality of second optical amplifiers coupled to the plurality of TX paths, respectively. Each of the plurality of second optical amplifiers can be a SOA. In some implementations, the device can include a plurality of second phase modulators coupled to the second optical path. The plurality of second phase modulators can include electro-optical modulators or liquid crystal modulators. Each of the plurality of second optical amplifiers can be formed / positioned / set between the plurality of second phase modulators and a corresponding one of the TX output ports.

[0099] In some implementations, the seed modulation device can include a control circuit configured to generate control signals to turn on / off each of the one or more first optical amplifiers and the plurality of second optical amplifiers based on electrical signals. In some implementations, the control circuit is not included in the device but is included in the lidar sensor system. The electrical signals can include one or more electromagnetic signals, such as one or more radio frequency (RF) signals. The control signals can indicate a time sequence for turning on / off each optical amplifier, thereby time-multiplexing the output of the optical amplifiers. For example, the device can time-multiplex the output signals of the plurality of second optical amplifiers according to the time sequence and activate / deactivate the output signals of the one or more first optical amplifiers in synchronization with the time sequence of the plurality of second optical amplifiers. In other words, the device can control the plurality of second optical amplifiers (e.g., SOAs) to time-multiplex the TX channels by turning on / off the plurality of TX paths. In some implementations, the device can output the signals of the plurality of second optical amplifiers according to a plurality of respective time sequences that are independent of each other.

[0100] In some embodiments, the seed modulation device can turn on / off each of the plurality of second optical amplifiers with high fidelity (e.g., with a suppression ratio of 20-25 dB). In some embodiments, the seed modulation device can turn on / off each SOA by forward biasing or reverse biasing the SOA. The device can forward bias the SOA to produce emission of photons, thereby passing the input optical signal through the SOA. On the other hand, the device can reverse bias the SOA to suppress optical gain, thereby turning off the input optical signal. For example, if the plurality of second optical amplifiers (e.g., SOAs) are all forward biased, when the input optical path receives a 20 milliwatt (mW) beam of light, the beam of light can be split into two 10 mW beams of light for the first and second optical paths, and further split into a plurality of beams of light (e.g., 2-5 mW beams of light) for the plurality of TX paths, respectively. On the other hand, if the plurality of second optical amplifiers (e.g., SOAs) are all unbiased (whether forward or reverse biased), a 1 mW beam of light can flow through each of the plurality of TX paths. If one of the SOAs is forward biased, it can output a 2-5 mW beam of light through the corresponding TX path, while if the SOA is reverse biased, it can output substantially no beam of light.

[0101] In some embodiments, the seed modulation device can turn on the first optical amplifier in synchronization with turning on one of the plurality of TX paths. In some embodiments, the device can turn on the first optical path in synchronization with turning on any of the plurality of TX paths. The device can turn on the first optical path by turning on the first SOA.

[0102] In some embodiments, the seed modulation device can include a plurality of LO paths branching off the first optical path at one end thereof. The device can include a plurality of third optical amplifiers coupled to the plurality of LO paths, respectively. Each of the plurality of third optical amplifiers can be an SOA. The device can time multiplex output signals of the plurality of third optical amplifiers according to a time sequence. In other words, the device can control the plurality of third optical amplifiers (e.g., SOAs) to time multiplex the LO channels by turning on / off the plurality of LO paths. In some embodiments, the device can output signals of the plurality of third optical amplifiers according to a plurality of respective time sequences that are independent of one another.

[0103] In some implementations, the seed modulation device may use one or more SOAs to perform amplitude modulation (AM) or phase modulation (PM). For example, the device may use multiple SOAs coupled to multiple second optical paths to perform AM or PM on an input optical signal to generate a modulated TX signal. Similarly, the device may use one or more SOAs coupled to a first optical path to perform AM or PM on an input optical signal to generate a modulated LO signal. In some implementations, the device may perform AM or PM on the input optical signal by changing or varying the drive current of each of the multiple SOAs. The device may perform AM or PM on the input optical signal by changing or varying the amplitude of the drive current of the SOA. In some implementations, the device may perform AM and PM on the input optical signal simultaneously by changing or varying the amplitude of the drive current of the SOA. In some implementations, the device may perform PM on the input optical signal by changing or varying the drive current of the SOA to change the effective length of the active region of the SOA. The device may perform AM or PM on the input optical signal in a multiplexed interleaved manner with the modulation of the optical signal. In this way, the device can slowly modulate the input optical signal to stabilize its phase (e.g., without phase drift) while performing modulation and multiplexing.

[0104] In some embodiments, control circuitry (which may or may not be included in the seed modulation device) may be configured to change or vary the drive current of one or more first optical amplifiers and each of a plurality of second optical amplifiers based on electrical signals to perform AM or PM on the input optical signal. In some embodiments, the electrical signals may include one or more electromagnetic signals, such as one or more RF signals. In some embodiments, the control signals may indicate (1) the timing sequence of turning each optical amplifier on / off and / or (2) the drive current of each optical amplifier.

[0105] In some embodiments, the seed modulation device may include all its components (e.g., optical paths, optical amplifiers, phase modulators, etc.) formed or disposed on a single substrate. In some embodiments, the seed modulation device 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. The III-V material may include at least one of indium phosphide (InP), indium arsenide (InAs), or gallium and arsenide (GaAs).

[0106] In some implementations, the seed modulator device can include at least one of a silicon photonic circuit, a photonic lightwave circuit (PLC), or a III-V semiconductor circuit, where all of its components (e.g., optical path, optical amplifier, phase modulator, etc.) are formed or disposed on a single substrate. In some implementations, all of the components of the device can be formed in a single layer to form a horizontal structure of an integrated circuit. In some implementations, the components of the device can be formed or disposed on multiple layers stacked on a single substrate to form a vertical structure of an integrated circuit. For example, the device can include a phase modulator implemented as one or more PLC modules, an optical path implemented as a silicon photonic circuit, and a SOA implemented as a III-V module, all arranged / formed on a single substrate.

[0107] According to certain aspects, implementations in the present disclosure relate to a device including an input optical path, a first optical path, a plurality of second optical paths, a first optical amplifier, a plurality of second optical amplifiers, and a control circuit. The input optical path can receive a light beam from a laser source at one end thereof. The first optical path and the plurality of second optical paths can branch from another end of the input optical path, respectively. The first optical amplifier can be coupled to the first optical path. The plurality of second optical amplifiers can be coupled to the plurality of second optical paths, respectively. The control circuit can selectively turn on one of the plurality of second optical amplifiers to output a modulated optical signal of the light beam. The control circuit can turn on the first optical amplifier in synchronization with turning on any one of the plurality of second optical amplifiers to output a local oscillator (LO) signal.

[0108] In some implementations, the plurality of second optical amplifiers can include a plurality of semiconductor optical amplifiers (SOAs). The control circuit can be configured to turn on or off the plurality of SOAs to time-multiplex output signals of the plurality of SOAs. The control circuit can be configured to vary a drive current of one of the plurality of SOAs to perform at least one of amplitude modulation or phase modulation of the light beam.

[0109] In some implementations, the device can include at least one of a silicon photonic circuit, a photonic lightwave circuit (PLC), or a III-V semiconductor circuit. The device can be a III-V semiconductor circuit.

[0110] In some implementations, the first optical amplifier can be a first SOA. The control circuit can be configured to turn on or off the first SOA according to a time sequence to output the LO signal. The control circuit can be configured to vary a drive current of the first SOA to perform at least one of amplitude modulation or phase modulation of the light beam.

[0111] In some embodiments, the first optical amplifier can include a plurality of third optical amplifiers. The control circuit can be configured to selectively turn on one of the plurality of third optical amplifiers to output a corresponding LO optical signal.

[0112] In some embodiments, the apparatus can further include one or more phase modulators coupled to the second optical path. The apparatus can further include one or more phase modulators coupled to the first optical path. The number of the one or more phase modulators coupled to the first optical path can be the same as the number of the one or more phase modulators coupled to the second optical path.

[0113] In some embodiments, the apparatus can further include a first output port coupled to one end of the first optical path, and a plurality of second output ports coupled to respective ends of the plurality of second optical paths. The control circuit can be configured to output the modulated optical signal of the optical beam to a corresponding one of the plurality of second output ports, and output the LO signal to the first output port.

[0114] In some embodiments, a light detection and ranging (lidar) system can include the apparatus, a laser source configured to generate the optical beam, a plurality of transmit (TX) channels, and one or more optical components. The one or more optical components can be configured to receive the first modulated optical signal and the first LO signal associated with the first modulated optical signal from the apparatus. The one or more optical components can be configured to receive the second modulated optical signal and the second LO signal associated with the second modulated optical signal from the apparatus. The one or more optical components can be configured to transmit the first modulated optical signal and the second modulated optical signal to an environment at a first TX channel and a second TX channel, respectively, among the plurality of TX channels. The one or more optical components can be configured to receive a first return optical signal and a second return optical signal reflected from one or more objects in the environment. The one or more optical components can be configured to pair the first return optical signal and the second return optical signal with the first LO signal and the second LO signal, respectively.

[0115] According to certain aspects, implementations in the present disclosure relate to a method of generating modulated optical signals in a circuit. The method can include receiving, by the circuit, a light beam from a laser source at an input optical path of the circuit. The circuit can include the input optical path, a first optical path and a plurality of second optical paths branching from the input optical path, respectively, a first optical amplifier coupled to the first optical path, and a plurality of second optical amplifiers coupled to the plurality of second optical paths, respectively. The method can include receiving, by the circuit, the light beam from the laser source at the input optical path. The method can include selectively turning on, by the circuit, one of the plurality of second optical amplifiers to output a modulated optical signal of the light beam. The method can include turning on, by the circuit, the first optical amplifier in synchronization with turning on any of the plurality of second optical amplifiers to output a local oscillator (LO) signal.

[0116] In some implementations, the plurality of second optical amplifiers can include a plurality of semiconductor optical amplifiers (SOAs). The method can include turning on or off one of the plurality of SOAs to time-multiplex output signals of the plurality of SOAs. The method can include varying a drive current of one of the plurality of SOAs to perform at least one of amplitude modulation or phase modulation of the light beam.

[0117] Various implementations in the present disclosure have one or more of the following advantages and benefits.

[0118] First, implementations in the present disclosure can provide useful techniques for efficiently performing time-multiplexing of TX signals and / or LO signals using optical amplifiers (e.g., SOAs) to overcome hardware requirements. For example, a seed modulation device according to some implementations can generate a plurality of modulated optical signals, and time-multiplex the plurality of modulated optical signals for a plurality of transmit (TX) channels and / or a plurality of (LO) channels. Such multiplexing can enable sharing of limited hardware resources (e.g., analog-to-digital converters (ADCs) or optical receivers / detectors).

[0119] Second, implementations in the present disclosure can provide useful techniques for stably performing modulation (e.g., AM or PM) by varying or changing a drive current of the SOAs. For example, the device can perform AM and / or PM of the input optical signal interleaved with multiplexing of the modulated optical signals. In this way, the device can slowly modulate the input optical signal to stabilize its phase (e.g., without phase drift) while performing modulation and multiplexing.

[0120] Third, embodiments in the present disclosure can provide useful technology for integrating components of a seed modulation device into an integrated circuit, thereby enabling significant cost savings (e.g., 5 times savings compared to conventional embodiments of circuits on printed circuit boards (PCBs)). For example, the seed modulation device can include at least one of a silicon photonic circuit, a photonic lightwave circuit (PLC), or a III-V semiconductor circuit, where all of its components (e.g., optical paths, optical amplifiers, phase modulators, etc.) are formed or disposed on a single substrate. In some embodiments, the seed modulation device can be an integrated photonic device based on III-V semiconductors, where all of its components are made of III-V materials and formed / disposed on a single substrate made of III-V materials.

[0121] FIG. 3A is a block diagram illustrating an example of a lidar system according to some embodiments. Environment 300 includes a lidar system 301 including a transmit (Tx) path and a receive (Rx) path, and one or more optics 310. The Tx path can include a laser source 302, a seed modulation device 350. The Tx path can include an amplifier (not shown) between the seed modulation device 350 and the one or more optics 310. The Rx path can include a mixer 308, a detector 312, and a transimpedance amplifier (TIA) 314. The laser source 302, the detector 312, and the TIA 314 can have similar configurations as the laser source 202, the detector 212, and the TIA 214, respectively.

[0122] The laser source 302 can be configured to provide an optical signal to the seed modulation device 350, which can be configured to modulate the amplitude, phase, and / or frequency of the optical signal based on one of radio frequency (RF) signals 321-1, 321-2, …, 321-N and using continuous wave (CW) modulation or quasi-CW modulation to generate corresponding modulated optical signals 341-1, 341-2, …, 341-N, respectively. The seed modulation device 350 can be configured to time-multiplex the modulated optical signals to an amplifier (not shown). The amplifier can be configured to amplify the (multiplexed) modulated optical signals to generate amplified optical signals to the optics 310.

[0123] In some implementations, the optics 310 can (1) receive a plurality of amplified optical signals (e.g., N amplified optical signals generated based on the modulated optical signals 341-1, 341-2, …, 341-N) via a plurality of different input channels (e.g., N different input channels), (2) transmit or steer the plurality of received amplified optical signals into the environment via a plurality of different TX channels (e.g., N different TX channels), and (3) receive a plurality of return signals reflected off one or more objects and provide the return signals to the mixers 308 via a plurality of different RX channels (e.g., N different RX channels). In some implementations, the mixers 308 can receive the return signals via a plurality of different channels (e.g., N different channels). For example, the optics 310 can be configured to steer the amplified optical signals it receives from the Tx path via each input channel into the environment within a given field of view, to the objects 318 via a corresponding TX channel, and then to receive the return signals reflected off the objects 318 via a corresponding RX channel and provide the return signals to the mixers 308 of the Rx path.

[0124] The seed modulation device 350 can be configured to modulate the amplitude, phase, and / or frequency of the optical signal based on the RF signal 325 and using continuous wave (CW) modulation or quasi-CW modulation to generate and send the modulated LO signal 345 to the mixers 308 of the Rx path.

[0125] In some implementations, the seed modulation device 350 can include the control circuit 320 configured to generate control signals to turn on / off one or more first optical amplifiers (e.g., the optical amplifier 362 in the optical amplifier 362) and a plurality of second optical amplifiers (e.g., the optical amplifiers 364-1, 364-2, …, 364-N in the optical amplifier 364) based on electrical signals (e.g., the RF signals 321-1, 321-2, …, 321-N). FIG. 3B FIG. 3B ​Each of the optical amplifiers 364-1, 364-2 in the seed modulation device 350. In some embodiments, the control circuit is not included in the seed modulation device 350, but is included in the lidar sensor system 301. The control signal can indicate the time sequence of turning each optical amplifier on / off, thereby time-multiplexing the output of the optical amplifier. For example, the device can time-multiplex the output signals of multiple second optical amplifiers (e.g., output optical signals 341-1, 341-2, ..., 341-N) according to the time sequence of the multiple second optical amplifiers, and activate / deactivate the output signal of one or more first optical amplifiers (e.g., output optical signal 345) in sync with the time sequence of the multiple second optical amplifiers. In some embodiments, the control circuit 320 can be configured to change or vary the drive current of one or more first optical amplifiers and each of the multiple second optical amplifiers based on electrical signals to perform amplitude modulation (AM) or phase modulation (PM) on the input optical signal. In some embodiments, the control circuit 320 can be configured to generate one or more control signals indicating (1) the time sequence of turning each optical amplifier on / off and / or (2) the drive current of each optical amplifier. Further details about the seed modulation device 350 will be provided in the following sections. FIG. 3B and FIG. 3C Describe it.

[0126] In some implementations, mixer 308 may be configured to mix (e.g., combine, multiply, etc.) the modulated LO signal with a return signal received from optics 310 at the channel to generate a down-converted signal and send the down-converted signal to detector 312. In some arrangements, mixer 308 may be configured to send the modulated LO signal to detector 312.

[0127] In some embodiments, the seed modulation device 350 may be configured to perform time multiplexing to send a first modulated optical (optical) signal (e.g., modulated optical signal 341-1) and a second modulated optical (optical) signal (e.g., modulated optical signal 341-1) to an amplifier ( FIG. 3A (Not shown in the image). The amplifier can be configured to amplify the first modulated optical signal and the second modulated optical signal to generate an amplified optical signal to the optical device 310. The seed modulation device 350 can be configured to (1) generate a first modulated LO signal associated with the first modulated optical signal in sync with the generation of the first modulated optical signal (e.g., generate a modulated LO signal 345 associated with the modulated optical signal 341-1 in sync with the generation of the modulated optical signal 341-1), and (2) generate a second modulated LO signal associated with the second modulated optical signal in sync with the generation of the first modulated optical signal (e.g., generate a modulated LO signal 345 associated with the modulated optical signal 341-2 in sync with the generation of the modulated optical signal 341-2).

[0128] Optical device 310 can be configured to redirect a first modulated optical signal and a second modulated optical signal (at different times) received from the Tx path to the environment within a given field of view toward object 318, receive corresponding first and second return signals reflected back from object 318, and provide the first and second return signals to mixer 308 of the Rx path. Seed modulation device 350 can be configured to send a first modulated LO signal and a second modulated LO signal to mixer 308 of the Rx path. Mixer 308 can be configured to pair the first return optical signal with the first modulated LO signal (e.g., associate, link, identify, etc.), and mix the first return 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 312. Similarly, mixer 308 can be configured to pair a second return optical signal with a second modulated LO signal, and mix the second return optical signal with the second modulated LO signal to generate a second down-converted signal and send the second down-converted signal to detector 312. Detector 312 can be configured to generate a first electrical signal and a second electrical signal based on the first down-converted signal and the second down-converted signal, respectively. Vehicle control system 120 can be configured to determine the distance to object 318 and / or measure the speed of object 318 based on the first electrical signal and the second electrical signal received via TIA 314.

[0129] FIG. 3B This is a block diagram illustrating an example of a seed modulation device according to some embodiments.

[0130] In some embodiments, the seed modulation device 350 may include an input optical path 351, a first optical path 355 branching from the input optical path 351 at one end (e.g., the left end of the first optical path 355), and a second optical path 353 branching from the input optical path at one end (e.g., the left end of the second optical path 353). The input optical path 351 may be formed / arranged / positioned between the first optical path 355 and the second optical path 353. For example, as FIG. 3B As shown, the input optical path 351 can be formed in the middle of the device 350, while the first optical path and the second optical path can be formed in the upper and lower parts of the device 350, respectively. The seed modulation device 350 can receive a light beam (or optical signal) at the input optical path 351. The device 350 can receive light from a laser source (e.g., FIG. 3A The optical signal of the laser source 302 in the device. The first optical path 355 can be used as a local oscillator (LO) path, while the second optical path 353 can be used as a TX path. The device may include multiple TX paths (e.g., TX paths 353-1 and 353-2) branching off from the second optical path 353 at one end (e.g., the left end of TX paths 353-1 and 353-2).

[0131] In some implementations, the seed modulating device 350 can include an input port 381 coupled to the input optical path 351 and configured to receive the optical signal from the laser source. The device 350 can include a LO output port 385 coupled / connected to another end (e.g., the right end) of the first optical path 355, and a plurality of TX output ports (e.g., TX output ports 383-1, 383-2) coupled / connected to another end of the plurality of TX paths, respectively.

[0132] In some implementations, the seed modulating device 350 can include one or more first optical amplifiers (e.g., optical amplifier 362) coupled to the first optical path 355. The one or more first optical amplifiers can include a SOA (e.g., SOA 362). In some implementations, the device can include a plurality of first phase modulators (e.g., phase modulators 361, 363) coupled to the first optical path 355. The plurality of first phase modulators can include electro-optic modulators or liquid crystal modulators. The one or more first optical amplifiers (e.g., optical amplifier 362) can be formed / disposed / positioned between the plurality of first phase modulators (e.g., phase modulators 361, 363) and the LO output port (e.g., LO output port 385).

[0133] In some implementations, the seed modulating device 350 can include a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2) coupled to the plurality of TX paths (e.g., TX paths 353-1, 353-2), respectively. Each of the plurality of second optical amplifiers can be a SOA (e.g., SOA 364-1, 364-2). The device can include a plurality of second phase modulators (e.g., phase modulators 365, 367) coupled to the second optical path 353. The plurality of second phase modulators can include electro-optic modulators or liquid crystal modulators. Each of the plurality of second optical amplifiers can be formed / disposed / positioned between the plurality of second phase modulators and a corresponding one of the TX output ports. For example, optical amplifier 364-1 can be formed between phase modulators 365, 367 and TX output port 383-1.

[0134] In some embodiments, the seed modulator device 350 can include a control circuit 320 configured to generate control signals (e.g., control signals 375-1, 375-2, 371) to turn on / off each of the one or more first optical amplifiers and the plurality of second optical amplifiers based on electrical signals (e.g., RF signals 321-1, 321-2, 325). For example, the control circuit 320 can receive the RF signals 321-1, 321-2, 325 and generate the control signals 375-1, 375-2, 371 to turn on / off the optical amplifiers 364-1, 364-2, 362, respectively, based on the RF signals 321-1, 321-2, 325. The control signals can indicate a time sequence to turn on / off each optical amplifier, thereby time-multiplexing the output of the optical amplifiers. For example, the control circuit 320 can time-multiplex the output signals of the plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2) according to a time sequence and turn on / off the output signals of the one or more first optical amplifiers (e.g., optical amplifier 362) in synchronization with the time sequence of the plurality of second optical amplifiers. The control circuit 320 can turn on the first optical amplifier (e.g., optical amplifier 362) in synchronization with turning on one of the plurality of TX paths (e.g., TX paths 353-1, 353-2) via the second optical amplifier (e.g., optical amplifiers 364-1, 364-2). The control circuit 320 can turn on the first optical path (e.g., optical path 355) via the first optical amplifier in synchronization with turning on any of the plurality of TX paths (e.g., TX paths 353-1, 353-2) via the second optical amplifier. For example, the control circuit 320 can turn on / off the first optical amplifier 362 simultaneously with turning on / off one of the plurality of second optical amplifiers 364-1, 364-2. In other words, the control circuit 320 can control the plurality of second optical amplifiers (e.g., SOAs) to time-multiplex the TX channels by turning on / off one of the plurality of TX paths 353-1, 353-2.

[0135] In some implementations, the control circuit 320 can turn on / off each of the plurality of second optical amplifiers with high fidelity (e.g., with 20-25 dB suppression ratio). The control circuit can turn on / off each SOA (e.g., SOA 362, 364-1, 364-2) by forward biasing or reverse biasing the SOA. For example, if all of the plurality of SOAs are forward biased, when the input optical path 351 receives a 20 milliwatt (mW) optical beam, the optical beam can be split into two 10 mW optical beams for the first optical path 355 and the second optical path 353, and further split into multiple optical beams (e.g., 2-5 mW optical beams) for the plurality of TX paths 353-1, 353-1, respectively. On the other hand, if none of the plurality of second SOAs are biased (whether forward or reverse biased), a 1 mW optical beam can flow through each of the plurality of TX paths 353-1, 353-2. If one of the SOAs is forward biased, it can output a 2-5 mW optical beam through the corresponding TX path, while if the SOA is reverse biased, it outputs substantially no optical beam.

[0136] In some implementations, seed modulator device 350 can perform amplitude modulation (AM) or phase modulation (PM) using one or more SOAs (e.g., SOAs 362, 364-1, 364-2). In some implementations, the electro-optical modulation effect can be implemented in InP SOAs using different quantum well (QW) structures or without using QWs (using only the intrinsic PN junction of InP). For example, device 350 can perform AM or PM on an input optical signal (e.g., an input optical signal received from input port 381) using multiple SOAs coupled to multiple second optical paths (e.g., TX paths 353-1, 353-2) to generate modulated TX signals. Similarly, device 350 can perform AM or PM on an input optical signal (e.g., an input optical signal received from input port 381) using one or more SOAs coupled to a first optical path (e.g., optical path 355) to generate modulated LO signals. Device 350 can perform AM or PM on an input optical signal by changing or varying a drive current of each of the multiple SOAs. Device 350 can perform both AM and PM on an input optical signal simultaneously by changing or varying the amplitude of the drive current of the SOAs. In some implementations, device 350 can change or vary the drive current (e.g., the current of control signal 371 of SOA 362) of the SOAs based on an electrical signal (e.g., RF signal 325) to change the effective length of the active region of the SOAs, thereby performing PM on the input optical signal. Device 350 can perform AM or PM (by changing the drive current of the SOAs) on an input optical signal interleaved with multiplexing (by turning on / off the SOAs) of the modulated optical signals. In this way, device 350 can slowly modulate the input optical signal to stabilize its phase (e.g., no phase drift) while performing modulation and multiplexing at the same time.

[0137] In some implementations, control circuit 320 (which can or can not be included in the seed modulator device) can be configured to change or vary a drive current of each of one or more first optical amplifiers and a plurality of second optical amplifiers (e.g., SOAs 364-1, 364-2, 362) based on an electrical signal (e.g., RF signals 321-1, 321-2, 325) to perform AM or PM on an input optical signal (e.g., an input signal received at input port 381). Control circuit 320 can change or vary the drive current of each optical amplifier using a control signal that indicates (1) a time sequence of turning on / off each optical amplifier and / or (2) a drive current of each optical amplifier.

[0138] In FIG. 3B some implementations, seed modulator device 350 can include photodiode 367, electrical pad 373, and an optical input port 389 for a photodiode monitor.

[0139] FIG. 3C is a block diagram illustrating an example of a seed modulation assembly 3000 according to some embodiments. The seed modulation assembly can include a housing 3010, a heat sink 3020, a cooler 3030, a seed modulation device / module / chip 350, a chip carrier 3040 that houses the seed modulation device 350, a fiber array 3060, a fiber cable 3070, an electrical feedthrough 3080, and / or an optical feedthrough 3090. The housing can be made of nickel-cobalt-iron alloy (e.g., Kovar). The heat sink 3020 can be made of CuW (copper tungsten). The cooler 3040 can be a thermoelectric cooler (TEC). The chip carrier 3040 can be made of ceramic or plastic. The fiber array 3060 can be a fiber array unit (FAU). The electrical feedthrough 3080 can be configured to provide electrical signals (e.g., RF signals) to the seed modulation device 350. The optical feedthrough 3090 can be configured to provide optical signals (e.g., light beams from a laser source) to the seed modulation device 350.

[0140] In some embodiments, the seed modulation device 350 can include all of its components (e.g., optical paths 351, 353, 355, optical amplifiers 362, 364-1, 364-2, phase modulators 361, 363, 365, 367, etc.) formed or disposed on a single substrate. The seed modulation device 350 can be an integrated photonic device based on III-V semiconductors, where all of its components are made of III-V materials and formed / disposed on a single substrate made of III-V materials. The III-V materials can include at least one of indium phosphide (InP), indium arsenide (InAs), or gallium and arsenide (GaAs).

[0141] In some embodiments, the seed modulation device 350 can include at least one of a silicon photonic circuit, a photonic lightwave circuit (PLC), or a III-V semiconductor circuit, where all of its components (e.g., optical paths 351, 353, 355, optical amplifiers 362, 364-1, 364-2, phase modulators 361, 363, 365, 367, etc.) are formed or disposed on a single substrate. In some embodiments, all of the components of the device can be formed in a single layer to form a horizontal structure of an integrated circuit. In some embodiments, the components of the device can be formed or disposed on multiple layers stacked on a single substrate to form a vertical structure of an integrated circuit. For example, the device 350 can include phase modulators (e.g., phase modulators 361, 363, 365, 367) implemented as one or more PLC modules, optical paths (e.g., optical paths 351, 353, 355) implemented as a silicon photonic circuit, and SOAs (e.g., 362, 364-1, 364-2) implemented as III-V modules, all disposed / formed on a single substrate.

[0142] FIG. 4 is a block diagram illustrating another example of a lidar system according to some embodiments.

[0143] The environment 400 includes a lidar system 401 including a transmit (Tx) path and a receive (Rx) path, and one or more optics 410. The Tx path can include a laser source 402, a seed modulation device 450. The Tx path can include an amplifier (not shown) between the seed modulation device 450 and the one or more optics 410. The Rx path can include a mixer 408, a detector 412, and a transimpedance amplifier (TIA) 414. The laser source 402, the detector 412, and the TIA 414 can have similar configurations as the laser source 302, the detector 312, and the TIA 314 shown in FIG. 3. FIG. 3A

[0144] The laser source 402 can be configured to provide an optical signal to the seed modulation device 450, which is configured to modulate the amplitude, phase, and / or frequency of the optical signal based on one of the radio frequency (RF) signals 421-1, 421-2, …, 421-N and using continuous wave (CW) modulation or quasi-CW modulation to generate a corresponding modulated optical signal 441-1, 441-2, …, 441-N, respectively. The seed modulation device 450 can be configured to time-multiplex the modulated optical signals to an amplifier (not shown). The amplifier can be configured to amplify the (multiplexed) modulated optical signals to generate amplified optical signals to the optics 410.

[0145] In some embodiments, the optics 410 can (1) receive a plurality of amplified optical signals (e.g., N amplified optical signals generated based on the modulated optical signals 441-1, 441-2, …, 441-N) via a plurality of different input channels (e.g., N different input channels), (2) transmit or steer the plurality of received amplified optical signals into the environment via a plurality of different TX channels (e.g., N different TX channels), and (3) receive a plurality of return signals reflected back from one or more objects via a plurality of different RX channels (e.g., N different RX channels) and provide the return signals to the mixer 408. In some embodiments, the mixer 408 can receive the return signals via a plurality of different channels (e.g., N different channels). For example, the optics 410 can be configured to steer the amplified optical signal it receives from the Tx path via each input channel into the environment via a corresponding TX channel to the object 418 within a given field of view, then receive a return signal reflected back from the object 418 via a corresponding RX channel and provide the return signal to the mixer 408 of the Rx path.

[0146] ​In some embodiments, the seed modulation device 450 may be configured to modulate the amplitude, phase, and / or frequency of an optical signal based on one of radio frequency (RF) signals 425-1, 425-2, ..., 425-N using continuous wave (CW) modulation or quasi-CW modulation, to generate corresponding modulated LO signals 445-1, 445-2, ..., 445-N, respectively. The seed modulation device 450 may be configured to time-multiplex the modulated LO signals to a mixer 408 in the Rx path. In some embodiments, the mixer 408 may receive multiple modulated LO signals (e.g., N modulated LO signals 445-1, 445-2, ..., 445-N) via multiple different LO channels (e.g., N different LO channels).

[0147] In some embodiments, the seed modulation device 450 may include at one end a second optical path (e.g., FIG. 3B The device 450 may include multiple TX paths branching off from the optical path 353 in the optical path. The device 450 may include multiple second optical amplifiers, each coupled to one of the multiple TX paths. Each of the multiple second optical amplifiers may be an SOA (Optical Signal Amplifier). The device can time-multiplex the output signals of the multiple second optical amplifiers according to a time sequence. In other words, the device 450 can control the multiple second optical amplifiers (e.g., SOAs) to time-multiplex the TX channels by turning the multiple TX paths on and off.

[0148] Similarly, seed modulation device 450 may include at one end of a first optical path (e.g., FIG. 3B The device may include multiple LO paths branching off from the optical path 355 in the optical path. The device may include multiple third optical amplifiers, each coupled to one of the multiple LO paths. Each of the multiple third optical amplifiers may be an SOA. The device may time-multiplex the output signals of the multiple third optical amplifiers according to a time sequence. In other words, the device 450 can control the multiple third optical amplifiers (e.g., SOAs) to time-multiplex the LO channels by turning the multiple LO paths on / off. In some embodiments, there may be a one-to-one correspondence between (1) the multiple LO paths (and the multiple third optical amplifiers coupled thereto) and (2) the multiple TX paths (and the multiple second optical amplifiers coupled thereto).

[0149] In some implementations, the seed modulation device 450 can include a control circuit 420 configured to generate control signals to turn on / off each of the plurality of second optical amplifiers based on the electrical signals (e.g., RF signals 421-1, 421-2,..., 421-N). In some implementations, the control circuit is not included in the seed modulation device 450, but is included in the lidar sensor system 401. The control signals can indicate a time sequence to turn on / off each of the second optical amplifiers, thereby time-multiplexing the output of the optical amplifiers. For example, the device can time-multiplex the output signals of the plurality of second optical amplifiers according to the time sequence and activate / deactivate the corresponding output signals of the plurality of third optical amplifiers (e.g., output optical signals 445-1, 445-2,..., 445-N) in synchronization with the time sequence of the plurality of second optical amplifiers.

[0150] In some implementations, the control circuit 420 can be configured to vary or change the drive current of each of the plurality of third optical amplifiers and the plurality of second optical amplifiers based on the electrical signals to perform amplitude modulation (AM) or phase modulation (PM) on the input optical signals. The control circuit 420 can be configured to generate one or more control signals indicating (1) a time sequence to turn on / off each of the optical amplifiers and / or (2) a drive current of each of the optical amplifiers.

[0151] In some implementations, the mixers 408 can be configured to mix (e.g., combine, multiply, etc.) the modulated LO signals received at a particular LO channel with the return signals received from the optical device 410 at the RX channel corresponding to the particular LO channel to generate down-converted signals and send the down-converted signals to the detectors 412. In some arrangements, the mixers 408 can be configured to send the modulated LO signals to the detectors 412.

[0152] In some implementations, the seed modulation device 450 can be configured to perform time-multiplexing to send the first modulated optical signals (e.g., modulated optical signals 441-1) and the second modulated optical signals (e.g., modulated optical signals 441-1) to the amplifiers (e.g., the plurality of second optical amplifiers and the plurality of third optical amplifiers) in a time-multiplexed manner. FIG. 4The amplifiers can be configured to amplify the first modulated optical signal and the second modulated optical signal to generate amplified optical signals to the optics 410 via respective TX channels. The seed modulation device 450 can be configured to (1) generate the first modulated LO signal associated with the first modulated optical signal in synchronization with the generation of the first modulated optical signal (e.g., generate the modulated LO signal 445-1 associated with the modulated optical signal 441-1 in synchronization with the generation of the modulated optical signal 441-1), and (2) generate the second modulated LO signal associated with the second modulated optical signal in synchronization with the generation of the first modulated optical signal (e.g., generate the modulated LO signal 445-2 associated with the modulated optical signal 441-2 in synchronization with the generation of the modulated optical signal 441-2).

[0153] The optics 410 can be configured to steer the first modulated optical signal and the second modulated optical signal (at different times) it receives from the Tx path into the environment within a given field of view to the object 418, can receive corresponding first return signal and second return signal reflected back from the object 418, and provide the first return signal and the second return signal to the mixers 408 of the Rx path. The seed modulation device 450 can be configured to send the first modulated LO signal and the second modulated LO signal to the mixers 408 of the Rx path via respective LO channels. The mixers 408 can be configured to pair (e.g., associate, link, identify, etc.) the first return optical signal with the first modulated LO signal and mix (e.g., combine, multiply, etc.) the first return optical signal with the first modulated LO signal to generate a first down-converted signal and send the first down-converted signal to the detector 412. Similarly, the mixers 408 can be configured to pair the second return optical signal with the second modulated LO signal and mix the second return optical signal with the second modulated LO signal to generate a second down-converted signal and send the second down-converted signal to the detector 412. The detector 412 can be configured to generate first electrical signal and second electrical signal based on the first down-converted signal and the second down-converted signal, respectively. The vehicle control system 120 can be configured to determine a distance to the object 418 and / or measure a speed of the object 418 based on the first electrical signal and the second electrical signal received via the TIA 414.

[0154] FIG. 5 is a flowchart illustrating an example method of generating modulated optical signals using a seed modulation device (e.g., the seed modulation device 350 in FIG. 3A , FIG. 3B , FIG. 3C the seed modulation device 350 in FIG. 4 ) in accordance with some embodiments. In some embodiments, the seed modulation device can be a circuit comprising: an input optical path (e.g., the input optical path 351 in FIG. 3B ), a first optical path (e.g., the first optical path 352 in ) branched from the input optical path, respectively, a second optical path (e.g., the second optical path 353 in ) branched from the input optical path, respectively, a first modulator (e.g., the first modulator 354 in ) coupled to the first optical path, a second modulator (e.g., the second modulator 355 in ) coupled to the second optical path, and a first LO path (e.g., the first LO path 356 in ) coupled to the first modulator and the second modulator.FIG. 3B and a plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B) coupled to the first optical path (e.g., optical path 355 in FIG. 3B). FIG. 3B and a first optical amplifier (e.g., optical amplifier 362 in FIG. 3B) coupled to the first optical path (e.g., optical path 355 in FIG. 3B). FIG. 3B and a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2 in FIG. 3B) respectively coupled to the plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B). FIG. 3B and a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2 in FIG. 3B) respectively coupled to the plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B). FIG. 3B and a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2 in FIG. 3B) respectively coupled to the plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B). FIG. 3B and FIG. 3C In some embodiments, the seed modulation device can include at least one of a silicon photonic circuit, a photonic lightwave circuit (PLC), or a III-V semiconductor circuit. The device can be a III-V semiconductor circuit. For example, referring to FIGS. 3A and 3B, the device 350 can include phase modulators (e.g., phase modulators 361, 363, 365, 367) implemented as one or more PLC modules, optical paths (e.g., optical paths 351, 353, 355) implemented as a silicon photonic circuit, and SOAs (e.g., 362, 364-1, 364-2) implemented as III-V modules, all of which are arranged / form on a single substrate.

[0155] In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the first optical amplifier and the plurality of second optical amplifiers (e.g., optical amplifiers 362, 364-1, 364-2 in FIG. 3B) can include one or more semiconductor optical amplifiers (SOAs). In some embodiments, the device can further include one or more phase modulators (e.g., phase modulators 365, 367 in FIG. 3B) coupled to the second optical paths (e.g., optical paths 353 in FIG. 3B). FIG. 3B In some embodiments, the device can further include a first output port (e.g., output port 385 in FIG. 3B) coupled to one end of the first optical path (e.g., optical path 355 in FIG. 3B), and a plurality of second output ports (e.g., output ports 386-1, 386-2 in FIG. 3B) coupled to respective ends of the plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B). FIG. 3B In some embodiments, the device can further include a first output port (e.g., output port 385 in FIG. 3B) coupled to one end of the first optical path (e.g., optical path 355 in FIG. 3B), and a plurality of second output ports (e.g., output ports 386-1, 386-2 in FIG. 3B) coupled to respective ends of the plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B). FIG. 3B In some embodiments, the device can further include a first output port (e.g., output port 385 in FIG. 3B) coupled to one end of the first optical path (e.g., optical path 355 in FIG. 3B), and a plurality of second output ports (e.g., output ports 386-1, 386-2 in FIG. 3B) coupled to respective ends of the plurality of second optical paths (e.g., optical paths 353-1, 353-2 in FIG. 3B). FIG. 5output port 383-1, 383-2 in FIG. 3B).

[0156] Referring back to FIG. 3B In this example method, the process 500 begins at step 520 by the circuit (e.g., circuit implementing the seed modulation device 350) receiving a light beam at an input optical path (e.g., input optical path 351) of the circuit from a laser source (e.g., laser source 202, 302, 402).

[0157] At step 540, in some implementations, the circuit (e.g., control circuit 320) can selectively turn on one of a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2 in FIG. 3B) to output a modulated optical signal of the light beam (e.g., modulated optical signal 341-1 in FIG. 3B). The circuit can be configured to output the modulated optical signal of the light beam to a corresponding one of a plurality of second output ports (e.g., output ports 383-1, 383-2 in FIG. 3B). FIG. 3A FIG. 3B At step 540, in some implementations, the circuit (e.g., control circuit 320) can selectively turn on one of a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2 in FIG. 3B) to output a modulated optical signal of the light beam (e.g., modulated optical signal 341-1 in FIG. 3B). The circuit can be configured to output the modulated optical signal of the light beam to a corresponding one of a plurality of second output ports (e.g., output ports 383-1, 383-2 in FIG. 3B). FIG. 3B

[0158] In some implementations, the plurality of second optical amplifiers can include a plurality of semiconductor optical amplifiers (SOAs). The control circuit can be configured to turn on or off the plurality of SOAs to time-multiplex the output signals of the plurality of SOAs. The circuit can be configured to vary a drive current of one of the plurality of SOAs to perform at least one of amplitude modulation (AM) or phase modulation (PM) of the light beam. For example, the circuit can be configured to perform at least one of AM or PM of the light beam by generating one or more control signals (e.g., control signals 371, 375-1, 375-2 in FIG. 3B) that indicate (1) a time sequence of turning on / off each optical amplifier and / or (2) a drive current of each optical amplifier. FIG. 3A

[0159] At step 560, in some implementations, the circuit (e.g., control circuit 320) can turn on a first optical amplifier (e.g., optical amplifier 362) in synchronization with turning on any of a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2) to output a local oscillator (LO) signal (e.g., LO signal 345 in FIG. 3B). The circuit can be configured to output the LO signal to a first output port (e.g., output port 385 in FIG. 3B). FIG. 3B FIG. 4 At step 560, in some implementations, the circuit (e.g., control circuit 320) can turn on a first optical amplifier (e.g., optical amplifier 362) in synchronization with turning on any of a plurality of second optical amplifiers (e.g., optical amplifiers 364-1, 364-2) to output a local oscillator (LO) signal (e.g., LO signal 345 in FIG. 3B). The circuit can be configured to output the LO signal to a first output port (e.g., output port 385 in FIG. 3B).

[0160] ​​​​In some embodiments, the first optical amplifier (e.g., optical amplifier 362) can be a first SOA. The circuit can be configured to turn on or off the first SOA according to the time sequence to output the LO signal. The circuit can be configured to vary a driving current of the first SOA to perform at least one of AM or PM of the optical beam.

[0161] In some embodiments, the first optical amplifier can include a plurality of third optical amplifiers. The circuit (e.g., control circuit 420 in FIG. 6 ) can be configured to selectively turn on one of the plurality of third optical amplifiers to output a corresponding LO optical signal (e.g., LO optical signals 445-1, 445-2, …, 445-N).

[0162] FIG. 3A to FIG. 3C is a flowchart illustrating an example method of controlling a lidar system using a seed modulation device (e.g., device 350 in FIG. 4 , device 450 in FIG. 3A ) according to some embodiments. In some embodiments, a lidar system (e.g., lidar sensor system 301 in FIG. 4 , lidar sensor system 401 in FIG. 3A ) can include a seed modulation device, a laser source (e.g., laser 302 in FIG. 4 , laser 402 in FIG. 3A ) configured to generate an optical beam, a plurality of transmit (TX) channels (e.g., TX channels 341-1, …, 341-N in FIG. 4 , TX channels 441-1, …, 441-N in FIG. 3A ) and one or more optical components (e.g., optical devices 310 in FIG. 4 , optical devices 410 in FIG. 3A ).

[0163] In this example method, process 600 begins at step 610 by receiving, by one or more optical components (e.g., optical devices 310), a first modulated optical signal and a first LO signal associated with the first modulated optical signal from a seed modulation device (e.g., device 350). At step 620, in some embodiments, the one or more optical components (e.g., optical devices 310) can be configured to receive, from the device (e.g., device 350), a second modulated optical signal and a second LO signal associated with the second modulated optical signal.

[0164] For example, with reference to FIG. 3AThe seed modulation device 350 can be configured to perform time multiplexing to send a first modulated optical (optical) signal (e.g., modulated optical signal 341-1) and a second modulated optical (optical) signal (e.g., modulated optical signal 341-1) to an amplifier ( FIG. 3A (Not shown in the image). The amplifier can be configured to amplify the first modulated optical signal and the second modulated optical signal to generate an amplified optical signal to the optical device 310. The seed modulation device 350 can be configured to (1) generate a first modulated LO signal associated with the first modulated optical signal in sync with the generation of the first modulated optical signal (e.g., generate a modulated LO signal 345 associated with the modulated optical signal 341-1 in sync with the generation of the modulated optical signal 341-1), and (2) generate a second modulated LO signal associated with the second modulated optical signal in sync with the generation of the first modulated optical signal (e.g., generate a modulated LO signal 345 associated with the modulated optical signal 341-2 in sync with the generation of the modulated optical signal 341-2).

[0165] In step 630, in some embodiments, one or more optical components may be configured to transmit a first modulated optical signal and a second modulated optical signal to the environment at a first TX channel and a second TX channel, respectively, among a plurality of TX channels. For example, refer to FIG. 3A Optical device 310 can be configured to redirect a first modulated optical signal and a second modulated optical signal (at different times) received from the Tx path to the environment within a given field of view toward object 318.

[0166] In step 650, in some embodiments, one or more optical components may be configured to receive a first reflected optical signal and a second reflected optical signal reflected from one or more objects in the environment. For example, refer to... FIG. 3A Optical device 310 can be configured to receive corresponding first return signal and second return signal reflected from object 318, and provide the first return signal and second return signal to mixer 308 of Rx path.

[0167] In step 650, in some embodiments, one or more optical components may be configured to pair a first return optical signal and a second return optical signal with a first LO signal and a second LO signal, respectively. For example, refer to FIG. 7The seed modulation device 350 can be configured to send the first modulated LO signal and the second modulated LO signal to the mixers 308 of the Rx path. The mixers 308 can be configured to pair (e.g., associate, link, identify, etc.) the first return optical signal with the first modulated LO signal and mix (e.g., combine, multiply, etc.) the first return optical signal with the first modulated LO signal to generate a first down-converted signal and send the first down-converted signal to the detector 312. Similarly, the mixers 308 can be configured to pair the second return optical signal with the second modulated LO signal and mix the second return optical signal with the second modulated LO signal to generate a second down-converted signal and send the second down-converted signal to the detector 312. The detector 312 can be configured to generate a first electrical signal and a second electrical signal based on the first down-converted signal and the second down-converted signal, respectively. The vehicle control system 120 can be configured to determine a distance to the object 318 and / or measure a speed of the object 318 based on the first electrical signal and the second electrical signal received via the TIA 314.

[0168] FIG. 7 is a block diagram illustrating an example of a computing system in accordance with some embodiments.

[0169] Referring to ​ The illustrated example computing system 700 includes one or more processors 710 that communicate with a memory 760 via a communication system 740 (e.g., a bus). The one or more processors 710 also communicate with at least one network interface controller 730 having a network interface port for connecting to a network (not shown) and other components, such as an input / output (“I / O”) component interface 750 that connects to a display (not shown) and an input device (not shown). Generally, the processor 710 will execute instructions (or computer programs) received from the memory. The illustrated processor 710 is coupled to or directly connected to a cache 720. In some instances, instructions are read from the memory 760 into the cache 720 and executed by the processor 710 from the cache 720.

[0170] In more detail, the processor 710 can be any logic circuitry that processes instructions (e.g., instructions fetched from the memory 760 or the cache 720). In some embodiments, the processor 710 is a microprocessor unit or a special purpose processor. The computing device 700 can be based on any processor or set of processors capable of operating as described herein. The processor 710 can be a single core or multi-core processor. The processor 710 can be a plurality of different processors.

[0171] Memory 760 can be any device suitable for storing computer readable data. Memory 760 can be a device with fixed storage or a device for reading a removable storage medium. Examples include all forms of non-volatile memory, media and memory devices, semiconductor memory devices (e.g., EPROM, EEPROM, SDRAM, and flash memory devices), magnetic disks, magneto-optical disks, and optical disks (e.g., CD ROM, DVD-ROM or Blu-Ray® disks). The computing system 700 can have any number of memory devices as memory 760.

[0172] Cache 720 is generally a form of computer memory that is placed in close proximity to processor 710 to enable fast read times. In some embodiments, cache 720 is part of processor 710 or is located on the same chip as processor 710. In some embodiments, there are multiple levels of cache 720, such as L2 and L3 cache levels.

[0173] Network interface controller 730 manages data exchange over a network interface, sometimes called a network interface port. Network interface controller 730 handles the physical and data link layers of the OSI model for network communications. In some embodiments, some of the tasks of a network interface controller are handled by one or more processors 710. In some embodiments, network interface controller 730 is part of processor 710. In some embodiments, computing system 700 has multiple network interfaces controlled by a single controller 730. In some embodiments, computing system 700 has multiple network interface controllers 730. In some embodiments, each network interface is a connection point for a physical network link (e.g., a cat-5 Ethernet link). In some embodiments, network interface controller 730 supports wireless network connections, and the interface port is a wireless (e.g., radio) receiver / transmitter (e.g., for any of the IEEE 802.11 protocols, near field communication “NFC”, Bluetooth, ANT, or any other wireless protocol). In some embodiments, network interface controller 730 implements one or more network protocols, such as Ethernet. In general, computing device 700 exchanges data with other computing devices via physical or wireless links over a network interface. The network interface can link to another device directly or via intermediate devices, such as network devices (such as hubs, bridges, switches, or routers) that connect computing device 700 to a data network, such as the Internet.

[0174] The computing system 700 can include one or more input or output ("I / O") devices or provide interfaces for one or more input or output ("I / O") devices. Input devices include, but are not limited to, keyboards, microphones, touch screens, foot pedals, sensors, MIDI devices, and pointing devices such as mice or track balls. Output devices include, but are not limited to, video displays, speakers, refreshable Braille terminals, lights, MIDI devices, and 2D or 3D printers.

[0175] Other components can include an I / O interface, an external serial device port, and any additional coprocessors. For example, the computing system 700 can include an interface (e.g., a universal serial bus (USB) interface) for connecting input devices, output devices, or additional memory devices (e.g., a portable flash drive or an external media drive). In some implementations, the computing device 700 includes additional devices, such as a coprocessor, for example, a math coprocessor can assist the processor 710 with high precision or complex calculations.

[0176] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Unless specifically stated otherwise, the term "some" refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the claims. Moreover, any combination of the

[0177] It should be understood that the particular order or hierarchy of steps in the processes disclosed is an example. Based upon design preferences, it should be understood that specific order or hierarchy of steps in the processes can be rearranged, while remaining within the scope of the previous description. The accompanying method claims present elements of the various steps in example order, and are not meant to be limited to the specific order or hierarchy presented.

[0178] The foregoing description of implementations has been presented for purposes of illustration and description. Various modifications to the implementations described herein will be readily apparent to those of ordinary skill in the art, and the general principles defined herein can be applied to other implementations without departing from the spirit or scope of the disclosure. Furthermore, the foregoing description has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the disclosure be limited only by the claims and equivalents thereof.

[0179] The various examples illustrated and described are provided merely as examples to illustrate various features of the claims. However, features shown and described with respect to any given example need not be limited to the associated example and can be used with or combined with other examples shown and described. Moreover, the claims are not intended to be limited by any one example.

[0180] The foregoing method descriptions and the flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the blocks of the various examples must be performed in the order presented. As will be appreciated by one of ordinary skill in the art, the order of blocks in the foregoing examples can be performed in any order. Words such as "thereafter," "then," "next," etc. are used merely to guide the reader through the description of examples. Additionally, any reference to claim elements in the singular, for example, using the articles "a," "an" or "the" is not nevertheless a limitation of the implementations to a single element, but encompasses a full range of elements: single or plural.

[0181] Various illustrative logical blocks, modules, circuits, and algorithm blocks described in connection with the examples disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and blocks have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0182] The hardware used to implement various illustrative logics, logical blocks, modules, and circuits described in connection with the examples disclosed herein can be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general purpose processor can be a microprocessor, but, in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Alternatively, some or all of the blocks or methods can be performed by circuitry dedicated to function described herein.

[0183] In some example embodiments, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored as one or more instructions or code on a non-transitory computer-readable storage medium or non-transitory processor-readable storage medium. The blocks of the methods or algorithms disclosed herein can be embodied in a processor-executable software module which can reside on a non-transitory computer- or processor-readable storage medium. Non-transitory computer- or processor-readable storage media can be any storage media that can be accessed by a computer or processor. By way of example but not limitation, such non-transitory computer- or processor-readable storage media can include RAM, ROM, EEPROM, FLASH memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other storage medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks and blu-ray discs where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of non-transitory computer- or processor-readable media. Additionally, the operations of methods or algorithms can reside in one or any combination or set of codes and / or instructions that can be resident on a non-transitory computer- or processor-readable storage medium and / or computer program product, such as a computer program product.

[0184] The foregoing description of the disclosed examples has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the examples to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the examples be limited not with this detailed description, but rather by the claims appended hereto.

Claims

1. A lidar system for light detection and ranging of vehicles, comprising: An input optical path, configured to receive a beam of light from a laser source; A first optical path and a plurality of second optical paths, wherein the first optical path and the plurality of second optical paths each branch from the input optical path; A first optical amplifier is coupled to the first optical path and configured to output a local oscillator (LO) signal. as well as A plurality of second optical amplifiers are coupled to a plurality of second optical paths, and one of the plurality of second optical amplifiers is selectively turned on to modulate the light beam received through the second optical path and output the modulated optical signal of the light beam.

2. The lidar system for light detection and ranging of a vehicle according to claim 1, wherein, The plurality of second optical amplifiers include one or more semiconductor optical amplifiers (SOAs).

3. The lidar system for light detection and ranging of vehicles according to claim 2, wherein, One of the one or more semiconductor optical amplifiers (SOAs) is turned on or off to perform signal modulation of the light beam.

4. The lidar system for light detection and ranging of a vehicle according to claim 2, wherein, One of the one or more semiconductor optical amplifiers (SOAs) is configured to change the drive current of the one or more semiconductor optical amplifiers (SOAs) to perform signal modulation of the light beam.

5. The lidar system for light detection and ranging for vehicles according to claim 1, wherein, The optical detection and ranging lidar system includes at least one of a silicon photonics circuit, a photonics wave circuit PLC, or a III-V semiconductor circuit.

6. The lidar system for light detection and ranging of a vehicle according to claim 1, wherein, The optical detection and ranging lidar system is a III-V semiconductor circuit, and The III-V semiconductor circuit includes at least one of indium phosphide (InP), indium arsenide (InAs), or gallium arsenide (GaAs).

7. The lidar system for light detection and ranging for vehicles according to claim 1, wherein, The first optical amplifier includes a plurality of third optical amplifiers. Among them, one of the plurality of third optical amplifiers is selectively turned on to output the corresponding local oscillator optical signal.

8. The lidar system for light detection and ranging for vehicles according to claim 1, wherein, The first optical amplifier includes a first semiconductor optical amplifier (SOA).

9. The lidar system for light detection and ranging for vehicles according to claim 8, wherein, The first semiconductor optical amplifier (SOA) is switched on or off to perform signal modulation of the beam.

10. The lidar system for light detection and ranging for vehicles according to claim 8, wherein, The first semiconductor optical amplifier (SOA) is configured to change the drive current of the first semiconductor optical amplifier (SOA) to perform signal modulation of the light beam.

11. The lidar system for optical detection and ranging of a vehicle according to claim 1, further comprising one or more phase modulators coupled to the first optical path or the second optical path. in, The one or more phase modulators are configured to perform phase modulation of the beam.

12. The lidar system for light detection and ranging for vehicles according to claim 11, further comprising: A control circuit configured to generate one or more control signals to turn the first optical amplifier and the plurality of second optical amplifiers on or off. The one or more control signals indicate the time sequence for turning the plurality of second optical amplifiers on or off.

13. The lidar system for light detection and ranging for vehicles according to claim 12, wherein, The control circuit is configured to turn the output signal of the first optical amplifier on or off in sync with the time sequence used to turn the plurality of second optical amplifiers on or off.

14. The lidar system for light detection and ranging for vehicles according to claim 12, wherein, The control circuit is configured to time-multiplex the output signals of the plurality of second optical amplifiers according to the time sequence.

15. A lidar system for light detection and ranging of a vehicle, comprising: The device includes: An input optical path, configured to receive a beam of light from a laser source; A first optical path and a plurality of second optical paths, wherein the first optical path and the plurality of second optical paths each branch from the input optical path; A first optical amplifier, coupled to the first optical path and configured to output a local oscillator (LO) signal; and A plurality of second optical amplifiers, each coupled to a plurality of second optical paths, wherein one of the second optical amplifiers is selectively switched on to modulate the light beam received through the second optical path and output a modulated optical signal of the light beam; and One or more optical components, the one or more optical components being configured to: Receive a first modulated optical signal and a first local oscillator (LO) signal associated with the first modulated optical signal from the device; Receive a second modulated optical signal and a second local oscillator (LO) signal associated with the second modulated optical signal from the device; The first modulated optical signal and the second modulated optical signal are respectively transmitted to the environment through the first transmission TX channel and the second transmission TX channel. Receive a first and a second returned optical signal reflected from one or more objects in the environment, and The first returned optical signal and the second returned optical signal are respectively paired with the first local oscillator LO signal and the second local oscillator LO signal.

16. An autonomous vehicle control system, comprising one or more processors, wherein, The one or more processors are configured to: This configures the input optical path to receive the beam from the laser source; This causes the first optical amplifier coupled to the first optical path to output a local oscillator (LO) signal, wherein the first optical path and a plurality of second optical paths branch off from the input optical path, and the plurality of second optical amplifiers are respectively coupled to the plurality of second optical paths; and Selectively turn on one of the plurality of second optical amplifiers to modulate the light beam received through the second optical path and output the modulated optical signal of the light beam.

17. The autonomous vehicle control system according to claim 16, wherein, The plurality of second optical amplifiers include one or more semiconductor optical amplifiers (SOAs).

18. An autonomous vehicle comprising a light detection and ranging lidar system and one or more processors, wherein, The optical detection and ranging lidar system includes: An input optical path, configured to receive a beam of light from a laser source; A first optical path and a plurality of second optical paths, wherein the first optical path and the plurality of second optical paths each branch from the input optical path; A first optical amplifier, coupled to the first optical path and configured to output a local oscillator (LO) signal; and A plurality of second optical amplifiers are provided, each coupled to a plurality of second optical paths. One of the second optical amplifiers is selectively switched on to modulate the light beam received through the second optical path and output a modulated optical signal of the light beam. The one or more processors are configured to operate the light detection and ranging lidar system to: The modulated optical signal is emitted into the environment. Receive the reflected optical signals from objects in the environment. The returned optical signal is paired with the local oscillator (LO) signal to generate an electrical signal, and The electrical signal is used to control at least one of the steering system and the braking system.

19. The autonomous vehicle according to claim 18, wherein, The plurality of second optical amplifiers include one or more semiconductor optical amplifiers (SOAs).

Images