High-resolution frequency-modulated continuous-wave lidar including solid-state beam steering

Abstract

A focal plane array (FPA) system of a solid-state frequency modulated continuous wave (FMCW) light detection and distance measurement (LiDAR) system is disclosed. The FPA system includes a switchable coherent pixel array (SCPA) and a lens system. The SCPA is located on a LiDAR chip and includes coherent pixels (CPs). Each CP is configured to emit coherent light. The lens system is positioned to direct the coherent light emitted from the SCPA into the environment as one or more light beams. Each of the one or more light beams is emitted at a specific angle, and the specific angle is partially based on the location of the coherent pixels on the LiDAR chip that generated the coherent light forming the one or more light beams.

Description

Technology Field

[0001] Cross-reference to related application(s)

[0002] This application claims priority under 35 USC §119(e) to U.S. Provisional Application No. 62 / 957,050 filed January 3, 2020 and U.S. Provisional Application No. 62 / 960,686 filed January 13, 2020, the entire contents of which are included by reference.

[0003] Technology field

[0004] The present disclosure generally relates to frequency modulated continuous wave (FMCW) light detection and ranging (LiDAR), and more specifically, to a solid-state FMCW LiDAR system. Background Technology

[0005] Conventional LiDAR systems use mechanical moving parts and bulk optical lens elements (i.e., refractive lens systems) to steer the laser beam. However, for many applications (e.g., automobiles), they are too bulky, expensive, and unreliable.

[0006] A solid-state Frequency Modulated Continuous Wave (FMCW) light detection and Light Detection and Range Measurement (LiDAR) system is configured to determine depth information of one or more objects within an environment. The solid-state FMCW LiDAR system includes a focal plane array (FPA) system and one or more laser sources. One or more laser sources (e.g., tunable laser arrays) provide light to the FPA system so that the FPA system generates one or more beams and scans said one or more beams across the environment (e.g., in two dimensions). The FPA system includes a Switchable Coherent Pixel Array (SCPA) and a lens system. The SCPA is located on the LiDAR chip and includes coherent pixels (CPs). Each CP is configured to emit coherent light. The lens system is positioned to direct the coherent light emitted from the SCPA into the environment as one or more light beams. And one or more light beams are each emitted at a specific angle, and said specific angle is partially based on the positions of CPs on the LiDAR chip that generated the coherent light forming said one or more light beams. Brief explanation of the drawing

[0007] Other advantages and features of the embodiments of the present disclosure will become more clearly apparent from the following detailed description in conjunction with the examples of the accompanying drawings and the appended claims. FIG. 1 shows an implementation of a switchable coherent pixel array on an integrated photonic LiDAR chip according to one or more embodiments. FIGS. 2a through 2d illustrate four versions of coherent pixels (CP) according to one or more embodiments. FIG. 3 illustrates a light beam steering structure in a solid-state FMCW LiDAR system according to one or more embodiments. FIG. 4a illustrates an optical beam steering structure for a solid-state FMCW LiDAR system including a transmission diffraction grating according to one or more embodiments. FIG. 4b illustrates an optical beam steering structure for a solid-state FMCW LiDAR system including a reflective diffraction grating according to one or more embodiments. Figure 5 illustrates examples of scanning and acquisition patterns generated by the solid-state LiDAR system of Figures 4a and 4b. FIG. 6 illustrates two synchronization methods between a CP and a laser source of a solid-state FMCW LiDAR system according to one or more embodiments. FIG. 7 illustrates a solid-state LiDAR system including an FPA system according to one or more embodiments. Specific details for implementing the invention

[0008] A LiDAR system determines depth information (e.g., distance, velocity, and acceleration of one or more objects) for the system's field of view. The LiDAR system is a Frequency Modulated Continuous Wave (FMCW) LiDAR. FMCW LiDAR directly measures the distance and velocity of an object by aiming a frequency-modulated, collimated light beam at a target. The signal, which is light reflected from the object, is mixed with a tapped version of the beam called a Local Oscillator (LO). The frequency of the resulting radio frequency (RF) bit signal is proportional to the distance from the LiDAR system to the object, provided that the Doppler shift, which requires additional measurement, is corrected. Two measurements, which may or may not be performed simultaneously, provide information on the distance and velocity of the target.

[0009] A solid-state FMCW LiDAR system is described herein. The solid-state LiDAR system includes a focal plane array (FPA) system and a laser source. The laser source provides coherent light to the FPA system. The FPA system may be an interactive system. The FPA system may include a lens system, a LiDAR chip, and additionally a diffraction grating. The LiDAR chip includes a solid-state 2D Switchable Coherent Pixels Array (SCA) positioned at a focal distance from the optical lens. The SCPA includes multiple Coherent Pixels (CPs). The FPA system can selectively activate the CPs to emit light (received from the laser source). Each CP includes an optical antenna and a coherent light receiver. The optical lens maps the direction of the incident beam to a focused spot position on the focal plane and maps the light emitted from the CPs to different angles in the environment (e.g., the peripheral area of ​​the solid-state FMCW LiDAR system) depending on the position of the CPs on the chip. The on-chip switch routes light to a selected CP and steers the beams to individual angular positions through an optical lens. The vertical and horizontal angles of the emitted light are determined by the position of the chip's optical antenna relative to the principal axis of the optical lens. Multi-channel individual beam steering is achieved by simultaneously switching multiple optical antennas using multiple switch networks.

[0010] In some embodiments, a diffraction grating (transmissive or reflective) is used to provide high-precision scanning performance. The diffraction grating is positioned to diffract one or more beams emitted from the lens system into the environment. The diffraction grating is a periodic structure that splits, refracts, or reflects light in multiple directions or by diffraction orders. The angle of the emitted light depends on the period of the grating, the wavelength of the optical beam, and the angle of incidence. A person skilled in the art can design the diffraction grating and the angle of incidence so that the light is directed mainly in one direction (e.g., a blazed grating), that is, generally only in the first order. In some embodiments, the solid-state FMCW LiDAR system includes a laser source, which is an adjustable light source, so that the FPA system can output a light beam over a wavelength range. Thus, by changing the wavelength of the light source, the solid-state FMCW LiDAR system can steer the emitted light between two separate steering positions set by the SCPA. Accordingly, it is possible to provide a finer scanning resolution than the scanning resolution associated with selectively activating different CPs.

[0011] Conventional FMCW LiDAR systems utilizing optical fibers and discrete optical components, such as optical interferometers, optical delay lines, and optical circulators, are bulky, expensive, and unreliable for use in many applications, such as automotive and robotics. In contrast, the solid-state LiDAR system described above overcomes these problems by integrating the aforementioned optical components, as well as optoelectronic components such as photodiodes and optical phase shifters, onto a single semiconductor chip. Furthermore, the solid-state LiDAR system can further reduce costs and form factor and improve reliability by realizing beam steering functions on the chip and eliminating mechanically moving parts from the system.

[0012] FIG. 1 illustrates an implementation of a switchable coherent pixel array (SCPA) on a photonic integrated LiDAR chip (111) according to one or more embodiments. The LiDAR chip is a photonic integrated circuit. The chip may include a plurality of basic function sub-arrays (100). Each sub-array (100) includes an optical input / output (I / O) port (102), an optional 1-to-K optical splitter (103), and one or more SCPAs (101), where K is an integer. The 1-to-K optical splitter (103) may be passive or active. Each optical I / O is supplied by a frequency-modulated light source provided by an off-chip or on-chip laser (e.g., a laser source). To reduce the number of optical I / Os, optical power may be distributed on-chip through an optional 1-to-K optical splitter. In the illustrated embodiment, each output of the 1-to-K optical splitter (103) is supplied to the corresponding SPCA (101). In the illustrated embodiments, each SCPA (101) includes M coherent pixels (105) and optical switch networks (104), where M is an integer. Note that in some cases, one or more optical switch networks (104), optional 1-to-K optical splitters (103), or some combination thereof may simply be referred to as an optical switch. An optical switch is configured to switchably couple an input port (102) to optical antennas within the coherent pixels, thereby forming optical paths between the input port and the optical antennas. An optical switch may include a plurality of active optical splitters. In some embodiments, the optical switch optically couples frequency-modulated laser signals to each optical antenna one at a time during the scanning period of the FMCW transceiver.

[0013] An optical switch network (104) selects one or more of M coherent pixels to transmit and receive frequency-modulated light (FM light) for distance measurement and detection. The coherent pixels may be physically arranged on a chip as a one-dimensional array (e.g., linear array) or a two-dimensional array (e.g., rectangular or regular array (e.g., non-random array such as a grid)). In some embodiments, the selected coherent pixel may transmit light into free space, receive the returning optical signals, perform coherent detection, and directly convert the optical signals into electrical signals for digital signal processing. Note that the received optical signals are not propagated back through the switch network so that they can be detected, but instead (though not shown in the illustrated embodiment) the outputs are routed individually, which reduces loss and consequently improves signal quality.

[0014] FIGS. 2a through 2d illustrate four versions of coherent pixels (CPs) according to one or more embodiments. In FIGS. 2a and 2b, light from an optical switch network is provided to an optical input port (203) of the CP. An optical splitter (212) splits the light into two output ports, referred to as a TX signal (205) and a local oscillator (LO: local oscillator, 214). The TX signal (215) is transmitted directly from the chip to the environment using a polarization splitting optical antenna (210) having one polarization (e.g., TM). The polarization splitting optical antenna (210) collects a beam reflected from a target object, combines orthogonal polarization (e.g., TE) into a waveguide (213), and transmits it directly to an optical mixer (201). In this case, the optical signal received by the polarization splitting optical antenna (210) is no longer split by an additional splitter or "pseudo-circulator." The signals received from the port (213) and LO (214) are mixed for coherent detection by an optical mixer (201), where the optical mixer (201) may be a balanced 2x2 optical combiner (201) as in FIG. 2a or an optical hybrid (209) as in FIG. 2b. Finally, a pair of photodiodes (PD, 207) in FIG. 2a and four PDs in FIG. 2b convert the optical signals into electrical signals for bit tone detection. This design implements a highly efficient integrated circulator for every single coherent pixel and enables an ultra-high sensitivity on-chip monostatic FMCW LiDAR. As illustrated in FIGS. 2c and 2d, the TX signal (215) and LO (214) may be supplied to the CP separately to provide additional flexibility. For example, the TX signal or local oscillator may be routed to the CP through two separate switch networks.

[0015] FIG. 3 illustrates an optical beam steering structure in a solid-state FMCW LiDAR system according to one or more embodiments. The solid-state FMCW LiDAR system includes a LiDAR chip (111) and a lens system (300). In the illustrated embodiment, CPs (105) of the SCPA on the LiDAR chip (111) are located at the focal length of the lens system (300). The lens system (300) includes one or more optical elements (e.g., positive lens, freeform lens, Fresnel lens, etc.) that map the physical location of each CP (105) to a unique direction. The lens system (300) is configured to project a transmission signal emitted from each of the plurality of antennas onto a corresponding part of the field of view (e.g., an area of ​​the environment) and to provide a reflection of said transmission signal to the antenna. Each optical antenna transmits and receives light at different angles. Thus, discrete optical beam scanning is achieved through switching to different antennas. The horizontal angle (θ) of the laser beam (301) h ) and vertical angle (θ v ) is set by the position of the CP containing the optical antenna with respect to the principal axis of the lens system (300). The SCPA may have the same or different step sizes when scanning in different directions. For example, SCPA-enabled discrete beam scanning, limited by the total number of CPs of the LiDAR chip (111), may have a dense angular step size in one dimension and a coarse angular step size in another dimension.

[0016] FIG. 4a illustrates an optical beam steering structure for a solid-state FMCW LiDAR system comprising a transmission diffraction grating (400) according to one or more embodiments. The solid-state FMCW LiDAR system comprises a LiDAR chip (111), a lens system (300), and a transmission diffraction grating (400). The LiDAR chip (111) and the lens system (300) operate as described with reference to FIG. 3 to generate a beam (400, 401) emitted into the environment. The transmission diffraction grating (400) changes the direction of the beam (400, 401) emitted from the lens system (300). The diffraction angle is changed by adjusting the optical wavelength of the input light source to the LiDAR chip (111), thereby allowing continuous steering between coarse discrete steering positions of the output from the lens system (300) (e.g., based on the position of the CP emitted light). For example, λ1, λ2, and λ3 represent three different optical wavelengths, and as illustrated, a transmission diffraction grating diffracts light of different wavelengths to different locations. Therefore, a solid-state FMCW LiDAR system emits light from different CPs to position the beam in a specific area of ​​the environment (i.e., coarse optical steering), and adjusts the wavelength of the emitted beam for finer optical steering (e.g., λ min from λ max (Law) It can be. The grating may be a 1D grating or a 2D grating. In some embodiments, the grating is a blazed grating designed to concentrate most of the power in a single order. In some embodiments, the grating is a custom 2D grating designed, for example, to suppress energy leaked in an unwanted higher order and to compensate for angular distortion of chromatic linear scanning that may occur with a 1D grating or some combination thereof.

[0017] FIG. 4b illustrates an optical beam steering structure for a solid-state FMCW LiDAR system including a reflective diffraction grating (410) according to one or more embodiments. The solid-state FMCW LiDAR system of FIG. 4b operates in substantially the same manner as the solid-state FMCW LiDAR system of FIG. 4a.

[0018] Accordingly, the gratings of FIGS. 4a and 4b are positioned to diffract one or more beams emitted from the lens system (300) into the environment, and the amount of diffraction is partially based on the wavelength of one or more beams. The solid-state FMCW LiDAR system can be modified to provide a second scanning resolution (i.e., the resolution of the grating) that is denser than the first scanning resolution by adjusting the wavelength of one or more beams over a wavelength range (i.e., partially based on the selective activation of different CPs of the SCPA).

[0019] FIG. 5 illustrates examples of scanning and acquisition patterns generated by the solid-state LiDAR system of FIG. 4a and 4b. λ min from λ max Through chromatic scanning up to, each coherent pixel can generate a section of a continuous line (hereinafter referred to as a scan line) in free space and can generate different coherent pixels (e.g., CPI, CP2) that map to different scan lines projected onto the environment.

[0020] FMCW LiDAR receives continuous signals for each scan line, which is typically much longer (e.g., 10–100 times) than the time window (e.g., several milliseconds) required to perform complete distance and velocity measurements and generate individual LiDAR points. Distance and velocity measurements in FMCW LiDAR are largely based on information extracted from a Fourier Transform in the form of a Fast Fourier Transform (FFT). For each scan line, an FFT can be performed on a continuous and non-overlapping segmentation of the continuous time-domain signal. For example, if the required time window is 10 μs and the scan line is 1 ms, typically 100 FFTs are performed to generate approximately 100 LiDAR points. The Sliding Discrete Fourier Transform (SDFT) can achieve much higher resolution compared to a standard Fast Fourier Transform (FFT) by interpolating the angular positions of continuous scans within each pixel group. SDFT allows the measurement interval (angle step size) to be set to a portion of the required time window. For example, if the time window is 10 μs and the scan line is 1 ms, and the measurement interval is set to 5 μs, approximately 200 LiDAR points can be generated through 200 SDFT executions. The number of LiDAR points is doubled compared to the case of a non-overlapping FFT. The smaller the measurement interval, the greater the number of points for a fixed scan line. Optional spatial overlap between scan lines of two adjacent subframes ensures sufficient headroom for the SDFT window to slide. In this way, a solid-state FMCW LiDAR system can project one or more beams into the environment. The solid-state FMCW LiDAR system includes an SCPA containing multiple CP groups. Each CP group corresponds to a different area of ​​the environment. A portion of one or more beams is reflected by objects within the environment and detected by at least two groups of CPs.A solid-state FMCW LiDAR system can use SDFT to interpolate the angular position of an object from the detected portions of one or more beams.

[0021] The FMCW laser source generates a frequency chirp synchronized with LiDAR pixels in the time domain. For each pixel, velocity and distance can be calculated simultaneously based on the Doppler effect by using one up ramp and one down ramp of the FMCW LiDAR's frequency response.

[0022] FIG. 6 illustrates two synchronization methods between a CP and a laser source of a solid-state FMCW LiDAR system according to one or more embodiments. The solid-state FMCW LiDAR system may be any one of the embodiments described herein. FIG. 6 shows two methods (A and B) for chirping the laser source of a solid-state FMCW LiDAR system. The horizontal axis represents time and the vertical axis represents frequency. In method A, the light is chirped so that the frequency response becomes a triangular waveform having a period equal to the pixel time of the SDFT. The solid-state FMCW LiDAR system scans the beam into the environment and measures the frequency of light reflected from objects within the environment during the scan. Each measurement takes a finite amount of time. Two measurements—one while the laser frequency increases linearly (up ramp) and the other while the laser frequency decreases linearly (down ramp)—are used for this single-point measurement. The pixel time represents a consecutive pair of up ramp and down ramp.

[0023] In Method B, a laser source (or sources) is chirped such that two complementary triangular chirped signals (denoted as Chirped 1 and Chirped 2) exist. These complementary chirped signals may be applied to the same light beam or to two separate beams. For example, in the case of two beams, the first laser light source is chirped to have a Chirped 1 frequency response, and the second laser light source is simultaneously chirped to have a Chirped 2 frequency response. Thus, the laser light sources are chirped simultaneously in a complementary manner (i.e., having the same pattern but with a phase difference of 180 degrees), providing simultaneous up-ramp and down-ramp measurements over a single pixel time. In an embodiment using a single laser source, the solid-state FMCW LiDAR system chirs the laser source (e.g., Chirped 1) and performs an up-ramp measurement on an object while scanning. Next, the solid-state FMCW LiDAR system chirs the beam in a complementary manner (e.g., Chirped 2) and performs a down-ramp measurement (for the same location on the object). In this case, the periods of the two chirp signals do not need to be the same as the time window required to perform a single Fourier transform. This relaxes the chirp bandwidth requirements for FMCW sources. Both methods ensure that the same duration is always verified for the frequency up-ramp and down-ramp within each SDFT window. By using CPs that generate complex signals (such as the I / Q of an optical hybrid), FMCW measurements (velocity and distance calculations) can be performed without ambiguity. Note that local frequency modulation can be added on top of a slowly changing wavelength sweep that can be used for chromatic scanning.

[0024] FIG. 7 illustrates a solid-state LiDAR system comprising an FPA system according to one or more embodiments. The FPA system may be an interactive system. The FPA system comprises an optical diffraction grating (705), a lens system (300), and a LiDAR chip (111). The diffraction grating may be a transmissive diffraction grating or a reflective diffraction grating, as previously discussed in FIG. 4a and 4b. The CPs within the LiDAR chip (111) are part of one or more SPCAs (101) controlled by an FPA driver (710). One or more individual CPs of the LiDAR chip (111) may be enabled to emit and receive light. The light emitted by the LiDAR chip (111) is generated by a Q-channel laser array (715). The Q-channel laser array (715) is a laser array having Q parallel channels, where Q is an integer. The Q-channel laser array (715) may be directly integrated with the LiDAR chip (111) or may be a separate module packaged together with the LiDAR chip (111). The Q-channel laser array (715) is controlled by a laser controller (720). In some embodiments, the Q-channel laser array (715) may be tunable over a certain wavelength range.

[0025] The laser controller (720) receives a control signal from the LiDAR processing engine (725) via a digital-to-analog converter (730). Additionally, the processing controls the FPA driver (710) and transmits and receives data from the LiDAR chip (111).

[0026] The LiDAR processing engine (725) includes a microcomputer (735). The microcomputer (735) processes data coming from the FPA system and transmits control signals to the FPA system through the FPA driver (710) and the laser controller (720). The LiDAR processing engine (725) also includes an N-channel receiver (740). The signal is received by the N-channel receiver (740), and the signal is digitized using a set of M-channel analog-to-digital converters (ADC, 745).

[0027] Additional configuration information

[0028] The drawings and the preceding description relate merely to preferred embodiments by way of example. It should be noted that alternative embodiments of the structures and methods disclosed herein as described above will be readily recognized as feasible alternatives that can be adopted without departing from the principles of the claims.

[0029] While the detailed description includes numerous details, they should not be interpreted as limiting the scope of the invention but merely as illustrating different examples. It should be understood that the scope of this disclosure includes other embodiments not discussed in detail above. Various other modifications, variations, and alterations that will be obvious to those skilled in the art may be made to the arrangement, operation, and details of the methods and apparatus disclosed herein without departing from the spirit and scope defined in the appended claims. Accordingly, the scope of the invention should be determined by the appended claims and their legal equivalents.

[0030] Alternative embodiments are implemented in computer hardware, firmware, software, and / or combinations thereof. Embodiments may be implemented as computer program products substantially embodied in machine-readable storage devices for execution by a programmable processor; method steps may be performed by a programmable processor executing an instruction program to perform functions by operating on input data and generating output. Embodiments may be implemented in one or more computer programs executable in a programmable system comprising, advantageously, a data storage system, at least one input device, and at least one output device, and at least one programmable processor coupled to receive data and instructions from and transmit data and instructions from the same. Each computer program may be implemented in a high-level procedural or object-oriented programming language, or, if desired, assembly or machine language; in any case, the language may be a compiled or interpreted language. Suitable processors include, for example, general-purpose and special-purpose microprocessors. Generally, the processor receives instructions and data from read-only memory (ROM) and / or random access memory (RAM). Generally, the computer will include one or more mass storage devices for storing data files; Such devices include magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for practically implementing computer program instructions and data include, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and all forms of non-volatile memory including CD-ROM disks.All of the aforementioned can be complemented or integrated with application-specific integrated circuits (ASICs) and other forms of hardware.

Claims

Claim 1 A focal plane array (FPA) system of a solid-state frequency modulated continuous wave (FMCW) light detection and distance measurement (LiDAR) system comprising: a switchable coherent pixel array (SCPA) on a LiDAR chip—the SCPA comprises an optical switch network and coherent pixels (CPs)—; and a lens system positioned to direct coherent light emitted from the SCPA into an environment as one or more light beams—each of which the one or more light beams are emitted at a specific angle, and which the specific angle is partially based on the position of the CPs on the LiDAR chip that generated the coherent light forming the one or more light beams—the optical switch network is configured to select one or more of the CPs, and each of the selected CPs is configured to emit the coherent light and perform coherent detection of a light beam reflected from an object in the environment among the one or more light beams. Claim 2 A focal plane array system according to claim 1, wherein the focal plane array system is configured to scan the one or more light beams in two dimensions within the environment at a first scanning resolution, partially based on the selective activation of different CPs of the SCPA. Claim 3 A focal plane array system according to claim 2, wherein the focal plane array system further comprises a diffraction grating positioned to diffract one or more light beams emitted from the lens system into the environment, wherein the amount of diffraction is partially based on the wavelength of the one or more light beams, and wherein the wavelength of the one or more light beams is adjusted over a certain wavelength range so as to change the amount of diffraction of the grating to provide a second scanning resolution denser than the first scanning resolution. Claim 4 A focal plane array system according to claim 3, wherein the diffraction grating is a blazed grating that emits light of a first diffraction order. Claim 5 A focal plane array system according to claim 3, wherein the diffraction grating is a reflective diffraction grating. Claim 6 A focal plane array system according to claim 3, wherein the diffraction grating is a transmission type diffraction grating. Claim 7 A focal plane array system according to claim 3, wherein a first set of CPs of the SCPA, the light emitted from each CP of the first set is mapped to each section of a first continuous line within the environment, and a second set of CPs of the SCPA, the light emitted from each CP of the second set is mapped to each section of a second continuous line within the environment that is different from the first continuous line. Claim 8 A focal plane array system according to claim 1, wherein a portion of one or more light beams is reflected by an object in the environment and detected by a group of at least two CPs of the SCPA, each group of CPs corresponds to a different region of the environment, and a Sliding Discrete Fourier Transform (SDFT) is used to interpolate the angular position of the object from the detected portion of the one or more light beams. Claim 9 A focal plane array system according to claim 8, wherein the frequency response of the light emitted by an FMCW source providing coherent light to the focal plane array system is a triangular waveform and has a period equal to the pixel time for the SDFT. Claim 10 A focal plane array system according to claim 8, wherein a first FMCW source and a second FMCW source are configured to provide coherent light to the focal plane array system, the first FMCW source is configured to emit light having a first frequency response that is triangular in a first phase, and the second FMCW source is configured to emit light having a second frequency response that is triangular in a second phase, the second phase being 180 degrees different from the first phase. Claim 11 A solid-state frequency-modulated continuous wave (FMCW) light detection and distance measurement (LiDAR) system comprising: a laser source emitting light; a switchable coherent pixel array (SCPA) on a LiDAR chip, wherein the SCPA comprises an optical switch network and coherent pixels (CPs), and is configured to selectively emit light through at least one of the CPs using light from at least the laser source; and a lens system positioned to direct the light emitted from the SCPA into an environment as one or more light beams, wherein each of the one or more light beams is emitted at a specific angle, and the specific angle is partially based on the position of the CPs on the LiDAR chip that generated the coherent light forming the one or more light beams, wherein the optical switch network is configured to select one or more of the CPs, and each of the selected CPs is configured to emit the coherent light and perform coherent detection of the light beam reflected from an object in the environment among the one or more light beams. Claim 12 A LiDAR system according to claim 11, wherein the LiDAR system further comprises a controller configured to instruct the LiDAR chip to scan the one or more light beams in two dimensions within the environment at a first scanning resolution, based partially on the selective activation of different CPs of the SCPA. Claim 13 The LiDAR system of claim 12, wherein the solid-state FMCW LiDAR system comprises: a diffraction grating positioned to diffract one or more light beams emitted from the lens system into the environment, wherein the amount of diffraction is partially based on the wavelength of the one or more light beams, and wherein the wavelength of the one or more light beams is adjusted over a certain wavelength range so as to change the amount of diffraction of the grating to provide a second scanning resolution denser than the first scanning resolution. Claim 14 A LiDAR system according to claim 13, wherein the diffraction grating is a blazed grating that emits light of a first diffraction order. Claim 15 A LiDAR system according to claim 13, wherein the diffraction grating is a reflective diffraction grating. Claim 16 A LiDAR system according to claim 13, wherein the diffraction grating is a transmission type diffraction grating. Claim 17 A LiDAR system according to claim 13, wherein a first set of CPs of the SCPA, the light emitted from each CP of the first set is mapped to each section of a first continuous line within the environment, and a second set of CPs of the SCPA, the light emitted from each CP of the second set is mapped to each section of a second continuous line within the environment that is different from the first continuous line. Claim 18 A LiDAR system according to claim 11, wherein a portion of one or more light beams is reflected by an object in the environment and detected by a group of at least two CPs of the SCPA, each group of CPs corresponds to a different region of the environment, and a Sliding Discrete Fourier Transform (SDFT) is used to interpolate the angular position of the object from the detected portion of the one or more light beams. Claim 19 A LiDAR system according to claim 18, wherein the frequency response of the coherent light is a triangular waveform and has a period equal to the pixel time for the SDFT. Claim 20 The LiDAR system of claim 18, wherein the light emitted from the laser source has a frequency response that is a triangular waveform in a first phase, and the FMCW LiDAR system is configured to emit light having a second frequency response that is a triangular waveform in a second phase, wherein the second phase is 180 degrees different from the first phase, and further comprises a second laser source, wherein the light emitted from the SCPA includes both the light emitted from the laser source and the light emitted from the second laser source.

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