Lidar with switchable local oscillator signal

Abstract

The present invention relates to LIDAR with switchable local oscillator signals. A light detection and ranging (LIDAR) sensor system includes a plurality of LIDAR pixels and a local oscillator module. The local oscillator module is coupled to the plurality of LIDAR pixels. The local oscillator module includes a first local oscillator input configured to receive a first local oscillator signal and a second local oscillator input configured to receive a second local oscillator signal. The local oscillator module is configured to provide the first local oscillator signal or the second local oscillator signal to a first LIDAR pixel of the plurality of LIDAR pixels.

Description

[0001] This application is a divisional application, which is directed against the parent application, which is the Chinese invention patent application filed on May 19, 2023, by Aurora Operations, entitled "LIDAR with Switchable Local Oscillator Signal", with application number 202380041079.X.

[0002] Related applications

[0003] This application is based on and claims the benefit of U.S. non-provisional patent application No. 18 / 161,441, filed January 30, 2023, and is a continuation-to-file of U.S. non-provisional patent application No. 18 / 160,817, filed January 27, 2023, and is a continuation-to-file of U.S. non-provisional patent application No. 17 / 750,247, filed May 20, 2022. This application also claims the benefit of U.S. non-provisional patent application No. 17 / 845,948, filed June 21, 2022. All such applications are incorporated herein by reference in their entirety. Background Technology

[0004] Frequency-modulated continuous wave (FMCW) optical detection and ranging (LIDAR) directly measures the range and speed of an object by emitting a frequency-modulated beam of light and detecting the returned signal. The automotive industry is currently developing autonomous features for controlling vehicles under specific conditions. According to SAE international standard J3016, autonomy is divided into six levels, from level 0 (no autonomy) to level 5 (the vehicle can operate without operator input under any conditions). Vehicles with autonomous features utilize sensors to perceive their environment. Acquiring and processing data from sensors allows the vehicle to navigate its environment. Summary of the Invention

[0005] Embodiments of this disclosure include a Light Detection and Ranging (LIDAR) sensor system comprising a plurality of LIDAR pixels and a local oscillator module. The local oscillator module is coupled to the plurality of LIDAR pixels. The local oscillator module includes a first local oscillator input configured to receive a first local oscillator signal and a second local oscillator input configured to receive a second local oscillator signal. The local oscillator module is configured to provide the first local oscillator signal and the second local oscillator signal to the first LIDAR pixel among the plurality of LIDAR pixels.

[0006] In one implementation, the LIDAR sensor system includes one or more processors and a transmit beam module. The transmit beam module is configured to receive a transmit beam. The one or more processors are configured to (i) drive the transmit beam module to provide a transmit beam to a first LIDAR pixel, and (ii) drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0007] In one embodiment, one or more processors are further configured to: drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to a second LIDAR pixel among a plurality of LIDAR pixels; and drive a transmit beam module to provide a transmit beam to the second LIDAR pixel, while the one or more processors drive the local oscillator module to provide the first local oscillator signal and the second local oscillator signal to the second LIDAR pixel.

[0008] In one implementation, the transmit beam module is configured to provide a transmit beam to a specific LIDAR pixel among a plurality of LIDAR pixels.

[0009] In one implementation, one or more processors are configured to drive a transmit beam module to provide a transmit beam to a first LIDAR pixel, while one or more processors drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0010] In an implementation, at least a first LIDAR pixel and a second LIDAR pixel among a plurality of LIDAR pixels include: (1) a transmitting optical antenna for transmitting a transmitting beam; (2) a receiving optical antenna for detecting a returning beam; (3) a first receiver configured to receive (i) a first polarization orientation of the returning beam; and (ii) a first local oscillator signal from a local oscillator module; and (4) a second receiver configured to receive (i) a second polarization orientation of the returning beam; and (ii) a second local oscillator signal from a local oscillator module.

[0011] In one embodiment, the receiving optical antenna includes: a first polarization receiving grating configured to direct a first polarization orientation of the returned beam to a first receiver; and a second polarization receiving grating configured to direct a second polarization orientation of the returned beam to a second receiver. The first polarization receiving grating and the second polarization receiving grating are spaced apart.

[0012] In one embodiment, the first receiver includes a first optical mixer and the second receiver includes a second optical mixer.

[0013] In one implementation, the local oscillator module is configured to provide a first local oscillator signal and a second local oscillator signal to only one specific LIDAR pixel among a plurality of LIDAR pixels at any given time.

[0014] In one embodiment, the LIDAR sensor system further includes a light source configured to emit near-infrared light; and a beam splitter configured to split the near-infrared light into a transmitted signal and a local oscillator signal. At least one of the first local oscillator signal and the second local oscillator signal originates from the local oscillator signal.

[0015] In one implementation, the local oscillator module includes at least two optical switches.

[0016] In one implementation, the first local oscillator signal has a first polarization orientation, and the second local oscillator signal has a second polarization orientation different from the first polarization orientation.

[0017] In this implementation, the first polarization orientation is orthogonal to the second polarization orientation.

[0018] Embodiments of this disclosure include an autonomous vehicle control system for an autonomous vehicle, the autonomous vehicle control system including a light detection and ranging (LIDAR) device and one or more processors. The one or more processors are configured to control the autonomous vehicle in response to a beat frequency signal. The LIDAR device includes a plurality of LIDAR pixels configured to generate the beat frequency signal and a local oscillator module. The local oscillator module is coupled to the plurality of LIDAR pixels. The local oscillator module includes a first local oscillator input configured to receive a first local oscillator signal and a second local oscillator input configured to receive a second local oscillator signal. The local oscillator module is configured to provide the first local oscillator signal and the second local oscillator signal to the first LIDAR pixel of the plurality of LIDAR pixels.

[0019] In one implementation, the autonomous vehicle control system further includes a transmit beam module configured to receive a transmit beam. One or more processors are configured to drive (i) the transmit beam module to provide a transmit beam to a first LIDAR pixel, and (ii) a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0020] In an implementation, one or more processors are further configured to: drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to a second first LIDAR pixel among a plurality of LIDAR pixels; and drive a transmit beam module to provide a transmit beam to the second first LIDAR pixel, while the one or more processors drive the local oscillator module to provide the first local oscillator signal and the second local oscillator signal to the second first LIDAR pixel.

[0021] In one implementation, the transmit beam module is configured to provide a transmit beam to a specific LIDAR pixel among a plurality of LIDAR pixels.

[0022] In one implementation, one or more processors are configured to drive a transmit beam module to provide a transmit beam to a first LIDAR pixel, while one or more processors drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0023] Embodiments of this disclosure include an autonomous vehicle comprising a Light Detection and Ranging (LIDAR) device and one or more processors configured to control the autonomous vehicle in response to a beat frequency signal. The LIDAR device includes a plurality of LIDAR pixels configured to generate the beat frequency signal and a local oscillator module coupled to the plurality of LIDAR pixels. The local oscillator module is coupled to the plurality of LIDAR pixels. The local oscillator module includes a first local oscillator input for receiving a first local oscillator signal and a second local oscillator input for receiving a second local oscillator signal. The local oscillator module is configured to selectively provide the first local oscillator signal and the second local oscillator signal to the first LIDAR pixel among the plurality of LIDAR pixels.

[0024] Embodiments of this disclosure include a Light Detection and Ranging (LIDAR) sensor system. The LIDAR sensor system includes a laser source configured to emit a laser beam. The LIDAR sensor system includes a beam splitter configured to split the laser beam into a transmit beam and a local oscillator signal. The LIDAR sensor system includes a polarization module configured to receive the local oscillator signal and generate a first local oscillator signal and a second local oscillator signal different from the first local oscillator signal. The LIDAR sensor system includes a plurality of LIDAR pixels. The LIDAR sensor system includes a transmit beam module coupled to the plurality of LIDAR pixels. The LIDAR sensor system includes a local oscillator module coupled to the plurality of LIDAR pixels, the local oscillator module including a first local oscillator input configured to receive the first local oscillator signal and a second local oscillator input configured to receive a second local oscillator signal. The LIDAR sensor system includes one or more processors configured to simultaneously drive the transmit beam, the first local oscillator signal, and the second local oscillator signal, one at a time, to specific LIDAR pixels among the plurality of LIDAR pixels to sequentially scan the plurality of LIDAR pixels. The LIDAR sensor system includes a power monitor coupled to a first LIDAR pixel, the power monitor being configured to detect the amount of power in the transmit beam supplied to the first LIDAR pixel.

[0025] In one implementation, one or more processors are configured to drive a transmit beam module to provide a transmit beam to a first LIDAR pixel, while one or more processors drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0026] In one implementation, the first LIDAR pixel includes: a first optical antenna configured to transmit a transmit beam; a second optical antenna configured to detect a return beam; a first receiver configured to receive (i) a first polarization orientation of the return beam and (ii) a first local oscillator signal from a local oscillator module; and a second receiver configured to receive (i) a second polarization orientation of the return beam and (ii) a second local oscillator signal from a local oscillator module.

[0027] In one embodiment, the second optical antenna includes a dual polarization receiving grating configured to: (i) direct a first polarization orientation of the returned beam to a first receiver, and (ii) direct a second polarization orientation of the returned beam to a second receiver.

[0028] In one embodiment, the second optical antenna includes a first polarization receiving grating configured to direct a first polarization orientation of the returned beam to the first receiver. The second optical antenna includes a second polarization receiving grating configured to direct a second polarization orientation of the returned beam to the second receiver. The first polarization receiving grating and the second polarization receiving grating are spaced apart.

[0029] In one embodiment, the first receiver includes a first optical mixer. The second receiver includes a second optical mixer.

[0030] In one implementation, the local oscillator module is configured to provide a first local oscillator signal and a second local oscillator signal to only one specific LIDAR pixel among a plurality of LIDAR pixels at any given time.

[0031] In one implementation, the local oscillator module includes multiple optical switches arranged in a multi-layer configuration.

[0032] In one implementation, the first local oscillator signal has a first polarization orientation. The second local oscillator signal has a second polarization orientation different from the first polarization orientation.

[0033] In this implementation, the first polarization orientation is orthogonal to the second polarization orientation.

[0034] Embodiments of this disclosure include an autonomous vehicle control system for autonomous vehicles. The autonomous vehicle control system includes a Light Detection and Ranging (LIDAR) system. The LIDAR system includes a laser source configured to emit a laser beam. The LIDAR system includes a beam splitter configured to split the laser beam into a transmit beam and a local oscillator signal. The LIDAR system includes a polarization module configured to receive the local oscillator signal and generate a first local oscillator signal and a second local oscillator signal different from the first local oscillator signal. The LIDAR system includes a plurality of LIDAR pixels. The LIDAR system includes a transmit beam module coupled to the plurality of LIDAR pixels. The LIDAR system includes a local oscillator module coupled to the plurality of LIDAR pixels. The local oscillator module includes a first local oscillator input configured to receive the first local oscillator signal and a second local oscillator input configured to receive the second local oscillator signal. The LIDAR system includes one or more processors configured to simultaneously drive a transmit beam, a first local oscillator signal, and a second local oscillator signal, one at a time, to specific LIDAR pixels among a plurality of LIDAR pixels to sequentially scan the plurality of LIDAR pixels. The LIDAR system includes a power monitor coupled to a first LIDAR pixel, the power monitor being configured to detect the amount of power in the transmit beam supplied to the first LIDAR pixel.

[0035] In one implementation, one or more processors are configured to drive a transmit beam module to provide a transmit beam to a first LIDAR pixel, while one or more processors drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0036] Embodiments of this disclosure include autonomous vehicles. The autonomous vehicle includes a Light Detection and Ranging (LIDAR) system. The LIDAR system includes a laser source configured to emit a laser beam. The LIDAR system includes a beam splitter configured to split the laser beam into a transmit beam and a local oscillator signal. The LIDAR system includes a polarization module configured to receive the local oscillator signal and generate a first local oscillator signal and a second local oscillator signal different from the first local oscillator signal. The LIDAR system includes a plurality of LIDAR pixels. The LIDAR system includes a transmit beam module coupled to the plurality of LIDAR pixels. The LIDAR system includes a local oscillator module coupled to the plurality of LIDAR pixels. The local oscillator module includes a first local oscillator input configured to receive the first local oscillator signal and a second local oscillator input configured to receive a second local oscillator signal. The LIDAR system includes one or more processors configured to simultaneously drive the transmit beam, the first local oscillator signal, and the second local oscillator signal, one at a time, to specific LIDAR pixels among the plurality of LIDAR pixels to sequentially scan the plurality of LIDAR pixels. The LIDAR system includes a power monitor coupled to a first LIDAR pixel, the power monitor being configured to detect the amount of power in the transmit beam supplied to the first LIDAR pixel.

[0037] In one implementation, the power monitor includes a detector.

[0038] In one implementation, the detector includes a photodiode.

[0039] In one embodiment, at least one of the local oscillator module or the transmit beam module includes a plurality of optical switches configured in a multilayer configuration.

[0040] In one embodiment, the local oscillator module includes a first plurality of optical switches arranged in a first multilayer configuration; and the transmit beam module includes a second plurality of optical switches arranged in a second multilayer configuration different from the first multilayer configuration.

[0041] In one implementation, the first multi-layer configuration includes more switches than the second multi-layer configuration.

[0042] In one implementation, the LIDAR sensor system includes a first waveguide coupled between a first local oscillator input of a polarization module and a local oscillator module; and a second waveguide coupled between a second local oscillator input of a polarization module and a local oscillator module.

[0043] In one embodiment, the power monitor further includes: a first waveguide through which the transmitted beam passes; and a second waveguide configured to receive a portion of the transmitted beam from the first waveguide. A detector configured to convert a portion of the transmitted beam into an electrical signal to support power monitoring.

[0044] Embodiments of this disclosure include a light detection and ranging (LIDAR) sensor. The LIDAR sensor includes a light source configured to transmit a light beam. The LIDAR sensor includes a beam splitter configured to split the light beam into a transmitted beam and a local oscillator signal. The LIDAR sensor includes a plurality of transmitters. The LIDAR sensor includes a switching device configured to receive the transmitted beam, the switching device including a plurality of optical switches arranged in a multi-layer configuration and operable to sequentially transmit the light beam to the plurality of transmitters.

[0045] In one embodiment, the multi-layer configuration includes a first layer comprising a first group of multiple optical switches. The multi-layer configuration also includes a second layer comprising a second group of multiple optical switches, the second group comprising more optical switches than the first group. Finally, the multi-layer configuration includes a third layer comprising a third group of multiple optical switches, the third group comprising more optical switches than the second group.

[0046] In one embodiment, the first group includes one optical switch, the second group includes two optical switches, and the third group includes four optical switches.

[0047] In one embodiment, the switching device further includes an optical device that couples the optical switches in the second group to the two optical switches in the third group.

[0048] In one implementation, the optical device includes a waveguide crossover.

[0049] In this implementation, the multiple optical switches are controlled independently.

[0050] In one implementation, multiple optical switches are operable to transmit the transmit beam one at a time to multiple transmitters.

[0051] In one implementation, a transmit beam emitted by a first transmitter among a plurality of transmitters is reflected from an object as a return beam, which is received by the first transmitter.

[0052] In one embodiment, the first transmitter includes a transmitting circuit configured to transmit a transmit beam and a receiver circuit configured to receive a return beam.

[0053] In this implementation, the light source includes a laser.

[0054] In one implementation, the LIDAR sensor includes a local oscillator configured to receive a local oscillator signal. The local oscillator includes multiple optical switches arranged in a multi-layer configuration and operable to sequentially transmit the local oscillator signal to multiple transmitters.

[0055] In one implementation, the LIDAR sensor includes a polarization module coupled between a local oscillator and a beam splitter. The polarization module is configured to receive a local oscillator signal and output a first local oscillator signal and a second local oscillator signal to the local oscillator, the first local oscillator signal having a first polarization orientation and the second local oscillator signal having a second polarization orientation different from the first polarization orientation.

[0056] In this implementation, the second polarization orientation is orthogonal to the first polarization orientation.

[0057] In one implementation, the LIDAR sensor includes a first interface for optically coupling a switching device to a plurality of transmitters and a second interface for optically coupling a local oscillator to a plurality of transmitters.

[0058] In one embodiment, at least the first transmitter among a plurality of transmitters includes a first optical antenna configured to emit a beam into the surrounding environment and a second optical antenna configured to detect the returning beam.

[0059] In one embodiment, the second optical antenna includes a dual-polarization optical antenna configured to detect a first polarization orientation and a second polarization orientation of the returning beam.

[0060] In one embodiment, at least the first transmitter among the plurality of transmitters further includes: a first coherent receiver configured to generate a first signal in response to receiving a first local oscillator signal and a first polarization orientation of the returned beam, and a second coherent receiver configured to generate a second signal in response to receiving a second local oscillator signal and a second polarization orientation of the returned beam.

[0061] In one implementation, the LIDAR sensor includes multiple power monitors configured to monitor the amount of power in a transmit beam emitted by a respective transmitter among a plurality of transmitters.

[0062] Embodiments of this disclosure include an autonomous vehicle control system. The autonomous vehicle control system includes a Light Detection and Ranging (LIDAR) system. The LIDAR system includes a light source configured to emit a light beam. The LIDAR system includes a beam splitter configured to split the light beam into a transmitted beam and a local oscillator signal. The LIDAR system includes a plurality of transmitters. The LIDAR system includes a switching device configured to receive the transmitted beam, the switching device including a plurality of optical switches arranged in a multi-layer configuration and operable to sequentially transmit the transmitted beam to the plurality of transmitters.

[0063] Embodiments of this disclosure include autonomous vehicles. The autonomous vehicle includes a Light Detection and Ranging (LIDAR) system. The LIDAR system includes a light source configured to emit a light beam. The LIDAR system includes a beam splitter configured to split the light beam into a transmitted beam and a local oscillator signal. The LIDAR system includes multiple transmitters. The LIDAR system includes a switching device configured to receive the transmitted beam. The switching device includes multiple optical switches arranged in a multi-layer configuration and operable to sequentially transmit the transmitted beam to the multiple transmitters.

[0064] Embodiments of this disclosure include a Light Detection and Ranging (LIDAR) sensor. The LIDAR sensor includes a light source configured to transmit a light beam. The LIDAR sensor includes a plurality of LIDAR pixels, each including: (i) a first optical antenna configured to transmit the light beam into the surrounding environment; and (ii) a second optical antenna configured to detect a returning beam indicating that the light beam is reflected from an object in the surrounding environment. The LIDAR sensor includes a switching device comprising a plurality of optical switches arranged in a multi-layer configuration, operable to sequentially transmit the light beam to corresponding LIDAR pixels among the plurality of LIDAR pixels to transmit the light beam into the surrounding environment. The LIDAR sensor includes a local oscillator module configured to receive one or more local oscillator signals and transmit one or more local oscillator signals to corresponding LIDAR pixels.

[0065] In one embodiment, the multi-layer configuration includes: a first layer comprising a first group of multiple optical switches; a second layer comprising a second group of multiple optical switches, the second group comprising more optical switches than the first group; and a third layer comprising a third group of multiple optical switches, the third group comprising more optical switches than the second group.

[0066] In one embodiment, the first group includes one optical switch, the second group includes two optical switches, and the third group includes four optical switches.

[0067] In one embodiment, the switching device further includes an optical device that couples the optical switches in the second group to the two optical switches in the third group.

[0068] In one implementation, the optical device includes a waveguide crossover.

[0069] In this implementation, the multiple optical switches are controlled independently.

[0070] In one implementation, multiple optical switches are operable to deliver beams one at a time to multiple LIDAR pixels.

[0071] In one implementation, one or more local oscillator signals include a first local oscillator signal having a first polarization and a second local oscillator signal having a second polarization different from the first polarization.

[0072] In one implementation, the local oscillator module includes a first local oscillator input configured to receive a first local oscillator signal and a second local oscillator input configured to receive a second local oscillator signal.

[0073] In this implementation, the second polarization is orthogonal to the first polarization.

[0074] In one embodiment, the second optical antenna includes a dual-polarization optical antenna configured to detect a first polarization orientation and a second polarization orientation of the returning beam.

[0075] In one embodiment, the light source includes a laser and the beam includes a laser beam.

[0076] In one implementation, the LIDAR sensor includes a power monitor configured to monitor the amount of power contained in the beam sent to the respective LIDAR pixel.

[0077] In one implementation, the LIDAR sensor includes one or more processors configured to: (i) drive a switching device to transmit a beam of light to a corresponding LIDAR pixel among a plurality of LIDAR pixels; and (ii) drive a local oscillator module to transmit one or more local oscillator signals to a corresponding LIDAR pixel.

[0078] In one implementation, one or more processors are configured to drive a local oscillator module to transmit one or more local oscillator signals to a corresponding LIDAR pixel, while one or more processors are configured to drive a switching device to transmit a beam to a corresponding LIDAR pixel.

[0079] In this implementation, multiple LIDAR pixels and a local oscillator module are mounted on the substrate.

[0080] In one implementation, each of the multiple LIDAR pixels also includes a receiver configured to convert the returned beam received by the second optical antenna into an electrical signal.

[0081] In one embodiment, the receiver includes one or more photodiodes.

[0082] Embodiments of this disclosure include an autonomous vehicle control system. The autonomous vehicle control system includes a Light Detection and Ranging (LIDAR) system. The LIDAR system includes a light source configured to emit a light beam. The LIDAR system includes a plurality of LIDAR pixels, each including: (i) a first optical antenna configured to transmit the light beam to the surrounding environment; and (ii) a second optical antenna configured to detect a returning beam indicating that the light beam is reflected from an object in the surrounding environment. The LIDAR system includes a switching device comprising a plurality of optical switches arranged in a multi-layer configuration, the plurality of optical switches being operable to selectively transmit the light beam to a corresponding LIDAR pixel among the plurality of LIDAR pixels to transmit the light beam to the surrounding environment. The LIDAR system includes a local oscillator module configured to receive one or more local oscillator signals and transmit one or more local oscillator signals to a corresponding LIDAR pixel.

[0083] Embodiments of this disclosure include autonomous vehicles. The autonomous vehicle includes a Light Detection and Ranging (LIDAR) system. The LIDAR system includes a light source configured to emit a light beam. The LIDAR system includes a plurality of LIDAR pixels, each including: (i) a first optical antenna configured to transmit the light beam to the surrounding environment; and (ii) a second optical antenna configured to detect a returning beam indicating that the light beam is reflected from an object in the surrounding environment. The LIDAR system includes a switching device comprising a plurality of optical switches arranged in a multi-layer configuration, the plurality of optical switches being operable to selectively transmit the light beam to a corresponding LIDAR pixel among the plurality of LIDAR pixels to transmit the light beam to the surrounding environment. The LIDAR system includes a local oscillator module configured to receive one or more local oscillator signals and transmit one or more local oscillator signals to a corresponding LIDAR pixel.

[0084] Embodiments of this disclosure include a Light Detection and Ranging (LIDAR) device. The LIDAR device includes a local oscillator network and one or more LIDAR pixels. The local oscillator network is configured to provide multiple local oscillator signals within the LIDAR device. The one or more LIDAR pixels are coupled to the local oscillator network. At least one of the one or more LIDAR pixels includes a transmitting optical antenna, a receiving optical antenna, and at least one receiver. The transmitting optical antenna is configured to transmit a transmitted beam. The receiving optical antenna is configured to detect (i) a first polarization orientation of the returned beam and (ii) a second polarization orientation of the returned beam. The at least one receiver is configured to generate at least one signal based on (i) the returned beam and (ii) at least one of the multiple local oscillator signals. The at least one signal represents the distance to an object.

[0085] In one embodiment, at least one of the plurality of local oscillator signals includes a first local oscillator signal and a second local oscillator signal. At least one receiver includes a first receiver configured to receive the first local oscillator signal, and at least one receiver includes a second receiver configured to receive the second local oscillator signal.

[0086] In one implementation, the first local oscillator signal has a first polarization orientation and the second local oscillator signal has a second polarization orientation.

[0087] In one embodiment, at least one signal includes a first signal and a second signal. A first receiver is configured to generate a first signal representing a return beam with a first polarization orientation, and a second receiver is configured to generate a second signal representing a return beam with a second polarization orientation.

[0088] In one embodiment, the first receiver includes a first optical mixer and a first diode pair configured to generate a first signal, and the second receiver includes a second optical mixer and a second diode pair configured to generate a second signal. The first signal and the second signal are electrical signals.

[0089] In one embodiment, the receiving optical antenna includes a first single-polarization grating coupler and a second single-polarization grating coupler. The first single-polarization grating coupler is configured to couple a first polarization orientation of the returned beam to at least one receiver. The second single-polarization grating coupler is configured to couple a second polarization orientation of the returned beam to at least one receiver.

[0090] In one embodiment, the transmitting optical antenna includes a third single-polarization grating coupler configured to transmit a transmit beam having a first polarization orientation. The first single-polarization grating coupler is offset from a second single-polarization grating coupler, and the second single-polarization grating coupler is offset from the third single-polarization grating coupler.

[0091] In one embodiment, the first single-polarization grating coupler is orthogonal to the second single-polarization grating coupler or can be rotated approximately 90 degrees relative to the second single-polarization grating coupler.

[0092] In one implementation, the local oscillator network includes a splitter configured to (i) receive a first local oscillator signal and (ii) provide multiple local oscillator signals to corresponding pixels among multiple LIDAR pixels.

[0093] In one implementation, the local oscillator network is configured to provide at least two of a plurality of local oscillator signals to each of a plurality of LIDAR pixels.

[0094] In one implementation, the LIDAR device also includes at least one passive beam splitter configured to couple a transmitted signal to at least two of one or more LIDAR pixels.

[0095] In one embodiment, the LIDAR device also includes multiple power monitors. One of the power monitors is coupled to the transmitting optical antenna. One of the power monitors includes at least one photodiode configured to generate an electrical output signal representing the amount of power of the transmitted signal.

[0096] In one embodiment, at least one of the plurality of LIDAR pixels further includes an optical rotator configured to couple a transmitted signal to a transmitted optical antenna and to couple a returned beam to at least one receiver.

[0097] In one embodiment, the transmitting optical antenna is located in a first semiconductor layer, and the receiving optical antenna is located in a second semiconductor layer stacked below the first semiconductor layer.

[0098] In one embodiment, the first semiconductor layer comprises a group III or group V element, and the second semiconductor layer is a nitride layer.

[0099] In this implementation, the first polarization orientation is orthogonal to the second polarization orientation.

[0100] Embodiments of this disclosure include an autonomous vehicle control system for an autonomous vehicle. The autonomous vehicle control system includes a light detection and ranging (LIDAR) device. The LIDAR device includes a local oscillator network and one or more LIDAR pixels. The local oscillator network is configured to provide a plurality of local oscillator signals within the LIDAR device. The one or more LIDAR pixels are coupled to the local oscillator network. At least one of the one or more LIDAR pixels includes a transmitting optical antenna, a receiving optical antenna, and at least one receiver. The transmitting optical antenna is configured to transmit a transmitted beam. The receiving optical antenna is configured to detect (i) a first polarization orientation of the returned beam and (ii) a second polarization orientation of the returned beam. The at least one receiver is configured to generate at least one signal based on (i) the returned beam and (ii) at least one of the plurality of local oscillator signals. The at least one signal represents the distance to an object.

[0101] In one embodiment, the receiving optical antenna includes a first single-polarization grating coupler and a second single-polarization grating coupler. The first single-polarization grating coupler is configured to couple a first polarization orientation of the returned beam to at least one receiver, and the second single-polarization grating coupler is configured to couple a second polarization orientation of the returned beam to at least one receiver.

[0102] In one embodiment, the transmitting optical antenna is located in a first semiconductor layer, and the receiving optical antenna is located in a second semiconductor layer stacked below the first semiconductor layer.

[0103] Embodiments of this disclosure include autonomous vehicles. The autonomous vehicle includes a Light Detection and Ranging (LIDAR) device. The LIDAR device includes a local oscillator network and one or more LIDAR pixels. The local oscillator network is configured to provide multiple local oscillator signals within the LIDAR device. The one or more LIDAR pixels are coupled to the local oscillator network. At least one of the one or more LIDAR pixels includes a transmitting optical antenna, a receiving optical antenna, and at least one receiver. The transmitting optical antenna is configured to transmit a transmitted beam. The receiving optical antenna is configured to detect (i) a first polarization orientation of the returned beam and (ii) a second polarization orientation of the returned beam. The at least one receiver is configured to generate at least one signal based on (i) the returned beam and (ii) at least one of the multiple local oscillator signals. The at least one signal represents the distance to an object.

[0104] Embodiments of this disclosure include a Light Detection and Ranging (LIDAR) sensor system for a vehicle. The LIDAR sensor system includes a laser source configured to emit a laser beam. The LIDAR sensor system includes a beam splitter configured to split the laser beam into a transmit beam and a local oscillator signal. The LIDAR sensor system includes a polarization module configured to receive the local oscillator signal and generate a first local oscillator signal and a second local oscillator signal different from the first local oscillator signal. The LIDAR sensor system includes a plurality of LIDAR pixels. The LIDAR sensor system includes a transmit beam module configured to provide a transmit beam to only one of the plurality of LIDAR pixels at any given time. The LIDAR sensor system includes a local oscillator module coupled to the plurality of LIDAR pixels, the local oscillator module including a first local oscillator input configured to receive the first local oscillator signal and a second local oscillator input configured to receive the second local oscillator signal. The LIDAR sensor system includes one or more processors configured to: (i) drive a transmit beam module to provide a transmit beam to a first LIDAR pixel among a plurality of LIDAR pixels; and (ii) drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel. The LIDAR sensor system includes a power monitor coupled to the first LIDAR pixel. The power monitor is configured to detect the amount of power in the transmit beam provided to the first LIDAR pixel.

[0105] In one implementation, one or more processors are configured to drive a transmit beam module to provide a transmit beam to a first LIDAR pixel, while one or more processors drive a local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0106] In one implementation, the first LIDAR pixel includes: a first optical antenna configured to transmit a transmit beam; a second optical antenna configured to detect a return beam; a first receiver configured to receive (i) a first polarization orientation of the return beam and (ii) a first local oscillator signal from a local oscillator module; and a second receiver configured to receive (i) a second polarization orientation of the return beam and (ii) a second local oscillator signal from a local oscillator module.

[0107] In one embodiment, the second optical antenna includes a dual polarization receiving grating configured to: (i) direct a first polarization orientation of the returned beam to a first receiver, and (ii) direct a second polarization orientation of the returned beam to a second receiver.

[0108] In one embodiment, the second optical antenna includes: a first polarization receiving grating configured to direct a first polarization orientation of the returned beam to a first receiver; and a second polarization receiving grating configured to direct a second polarization orientation of the returned beam to a second receiver. The first polarization receiving grating and the second polarization receiving grating are spaced apart.

[0109] In one embodiment, the first receiver includes a first optical mixer, and the second receiver includes a second optical mixer.

[0110] In one implementation, the local oscillator module is configured to provide a first local oscillator signal and a second local oscillator signal to only one specific LIDAR pixel among a plurality of LIDAR pixels at any given time.

[0111] In one implementation, the first local oscillator signal has a first polarization orientation. The second local oscillator signal has a second polarization orientation different from the first polarization orientation.

[0112] In this implementation, the first polarization orientation is orthogonal to the second polarization orientation.

[0113] In one embodiment, at least one of the local oscillator module or the transmit beam module includes a plurality of optical switches configured in a multilayer configuration.

[0114] In one embodiment, the local oscillator module includes a first plurality of optical switches arranged in a first multi-layer configuration. The transmit beam module includes a second plurality of optical switches arranged in a second multi-layer configuration different from the first multi-layer configuration.

[0115] In one implementation, the first multi-layer configuration includes more switches than the second multi-layer configuration.

[0116] In one implementation, the power monitor includes a detector. The power monitor also includes a first waveguide through which the transmitted beam passes and a second waveguide configured to receive a portion of the transmitted beam from the first waveguide. The detector is configured to convert a portion of the transmitted beam into an electrical signal to support power monitoring.

[0117] Embodiments of this disclosure include an autonomous vehicle control system for autonomous vehicles. The autonomous vehicle control system includes a light detection and ranging (LIDAR) system as described above.

[0118] Embodiments of this disclosure include autonomous vehicles that include the light detection and ranging (LIDAR) system of any of the above claims. Attached Figure Description

[0119] Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following drawings, wherein, unless otherwise specified, similar reference numerals in the various views refer to similar parts.

[0120] Figure 1A A block diagram illustrating an example of the system environment of an autonomous vehicle according to an embodiment of the present disclosure is shown.

[0121] Figure 1B shows a block diagram of an example system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure.

[0122] Figure 1C shows a block diagram of an example system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure.

[0123] Figure 1D shows a block diagram of an example system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure.

[0124] Figure 2 A LIDAR system including a local oscillator module according to an embodiment of the present disclosure is shown.

[0125] Figure 3 The embodiments shown in this disclosure may include... Figure 2 An example diagram of a LiDAR transceiver, a component of a LiDAR system.

[0126] Figure 4 An example local oscillator module according to an embodiment of this disclosure is shown.

[0127] Figure 5 An example transmit beam module according to an embodiment of this disclosure is shown.

[0128] Figure 6 An example LIDAR pixel including a first coherent receiver and a second coherent receiver is shown according to an embodiment of the present disclosure.

[0129] Figure 7 An example coherent receiver according to an embodiment of this disclosure is shown.

[0130] Figure 8 The process of operating a LIDAR device according to an embodiment of this disclosure is illustrated.

[0131] Figure 9 A block diagram of a LiDAR system including a LiDAR transceiver according to an embodiment of the present disclosure is shown.

[0132] Figure 10A A schematic diagram of a LiDAR transceiver having a local oscillator network and a LiDAR pixel array according to an embodiment of the present disclosure is shown.

[0133] Figure 10B A schematic diagram of a LiDAR transceiver having a local oscillator network and a LiDAR pixel array according to an embodiment of the present disclosure is shown.

[0134] Figure 11 A LIDAR pixel with a dual-polarization optical antenna according to an embodiment of the present disclosure is shown.

[0135] Figure 12A and 12B A block diagram showing a stacked configuration of optical antennas of a LIDAR device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0136] This document describes an implementation of optical detection and ranging (LIDAR) with a switchable local oscillator signal. Numerous specific details are set forth in the following description to provide a comprehensive understanding of the implementation. However, those skilled in the art will recognize that the techniques described herein can be implemented without one or more of these specific details, or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring certain aspects.

[0137] The references to "one embodiment" or "implementation" in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0138] Several technical terms are used in this specification. These terms should be used in their ordinary sense in the field of their respective domains, unless otherwise expressly defined herein or the context of their use clearly implies otherwise. For the purposes of this specification, the term "autonomous vehicle" includes vehicles that possess autonomous characteristics of any level of autonomy as defined in SAE International Standard J3016.

[0139] In various aspects of this disclosure, visible light can be defined as having a wavelength range of about 380 nm to 700 nm. Non-visible light can be defined as light having wavelengths outside the visible light range, such as ultraviolet and infrared light. Infrared light with a wavelength range of about 700 nm to 1 mm includes near-infrared light. In various aspects of this disclosure, near-infrared light can be defined as having a wavelength range of about 700 nm to 1600 nm.

[0140] Frequency-modulated continuous wave (FMCW) LiDAR directly measures the range and velocity of an object or target by sending a frequency-modulated beam of light. The light reflected from the object / target can be combined with a tapped version of the beam. Once the Doppler shift required for the second measurement is corrected, the frequency of the resulting beat signal is proportional to the distance between the object and the LiDAR system. The two measurements, which can be performed simultaneously or separately, provide both range and velocity information.

[0141] Embodiments of this disclosure include a LIDAR system and apparatus using switchable local oscillator signals. The LIDAR apparatus may include multiple LIDAR pixels. Each LIDAR pixel may have a transmit optical antenna for transmitting a transmit beam and at least one receive optical antenna for detecting a return beam of the transmit beam reflected as a target from the environment. Each LIDAR pixel may have multiple optical receivers that receive different local oscillator signals. For example, a first optical receiver of the LIDAR pixel may receive a first oscillator signal with a first polarization orientation, and a second optical receiver of the LIDAR pixel may receive a second local oscillator signal with a second polarization orientation different from the first polarization orientation. The first optical receiver may receive the first polarization orientation of the return signal, and the second optical receiver may receive the second polarization orientation of the return signal. Previously, a first local oscillator signal and a second local oscillator signal could be provided to each LIDAR pixel simultaneously. However, this technique consumes optical power and also generates optical noise, which may result in a weak signal-to-noise ratio (SNR) for detecting the return beam.

[0142] In embodiments of this disclosure, a local oscillator module is configured to receive a first local oscillator signal and a second local oscillator signal. The local oscillator module is configured to selectively provide the first and second local oscillator signals to a beam-emitting LIDAR pixel among a plurality of LIDAR pixels. While providing the first and second local oscillator signals to the beam-emitting LIDAR pixel, a transmit beam (e.g., infrared laser) can be provided to the beam-emitting LIDAR pixel. A transmit beam module can be configured to provide the transmit beam to any pixel among the plurality of LIDAR pixels that serves as a beam-emitting LIDAR pixel. In this way, the transmit beam and the first and second local oscillator signals can be selectively (simultaneously in some embodiments) provided to a LIDAR pixel to scan a plurality of LIDAR pixels. A beam-emitting LIDAR pixel is a LIDAR pixel that receives the transmit beam, the first local oscillator signal, and the second local oscillator signal at a given time.

[0143] Each of a plurality of LiDAR pixels may include a transmit optical antenna, a receive optical antenna, a first receiver, and a second receiver. The transmit optical antenna is configured to transmit a transmit beam. The receive optical antenna is configured to detect a return beam. The first receiver may be configured to receive a first polarization orientation of the return beam and a first local oscillator signal from a local oscillator module. The second receiver may be configured to receive a second polarization orientation of the return beam and a second local oscillator signal from a local oscillator module. The first local oscillator signal may have a polarization orientation orthogonal to the second local oscillator signal. The first and second receivers may generate a first beat frequency signal and a second beat frequency signal. These beat frequency signals may be used to generate a LiDAR image of the environment. These and other embodiments are described in more detail with reference to Figures 1-12B.

[0144] 1. System environment of autonomous vehicles

[0145] Figure 1A This is a block diagram illustrating an example of the system environment of an autonomous vehicle according to some implementation methods.

[0146] See Figure 1AAn example autonomous vehicle 110A may be implemented, incorporating various technologies disclosed herein. For example, vehicle 110A may include: a powertrain 192 comprising a prime mover 194 driven by energy source 196 and capable of supplying power to transmission system 198; and a control system 180 comprising steering control 182, powertrain control 184, and braking control 186. Vehicle 110A can be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or goods and capable of operating in a variety of environments, and it should be understood that the aforementioned components 180-198 can vary widely depending on the type of vehicle in which these components are used.

[0147] 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 may include one or more electric motors and / or internal combustion engines (etc.). Energy sources may include, for example, fuel systems (e.g., providing gasoline, diesel, hydrogen, etc.), battery systems, solar panels or other renewable energy sources, and / or fuel cell cell systems. The drivetrain 198 may include wheels and / or tires, as well as 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 down the vehicle 110A, and directional or steering components suitable for controlling the trajectory of the vehicle 110A (e.g., rack and pinion steering linkages that enable one or more wheels of the vehicle 110A to pivot about a generally vertical axis to change the angle of the wheel's plane of rotation relative to the vehicle's longitudinal axis). In some embodiments, a combination of powertrain and energy source may be used (e.g., in the case of an electric / gas hybrid vehicle), and in some cases, multiple electric motors (e.g., dedicated to individual wheels or axles) may be used as prime movers.

[0148] The steering controller 182 may include one or more actuators and / or sensors for controlling and receiving feedback from the steering or directional components to enable the vehicle 110A to follow a desired trajectory. The powertrain control 184 may be configured to control the output of the powertrain 192, for example, controlling the output power of the prime mover 194 to control the gear position of the transmission in the drivetrain 198, thereby controlling the speed and / or direction of the vehicle 110A. The braking control 186 may be configured to control one or more brakes, such as disc brakes or drum brakes coupled to the wheels of the vehicle 110A, to slow down or stop it.

[0149] Other vehicle types (including but not limited to off-road vehicles, all-terrain or tracked vehicles, construction equipment, etc.) will inevitably use different powertrains, drivetrains, energy sources, steering control, powertrain control, and braking control. Furthermore, in some embodiments, certain components can be combined; for example, vehicle steering control is primarily handled by altering the output of one or more prime movers. Therefore, the embodiments disclosed herein are not limited to the specific applications of the techniques described herein in autonomous wheeled land vehicles.

[0150] Various levels of autonomous control of the vehicle 110A can be achieved in the vehicle control system 120, which may include one or more processors 122 and one or more memories 124, each processor 122 being configured to execute program code instructions 126 stored in the memory 124. The processors may include, for example, a graphics processing unit (“GPU”) and / or a central processing unit (“CPU”).

[0151] Sensor 130 may include various sensors suitable for collecting information from the vehicle's surrounding environment for controlling the vehicle's operation. For example, sensor 130 may include a radar sensor 134, a LiDAR (Light Detection and Ranging) sensor 136, a 3D positioning sensor 138, such as an accelerometer, gyroscope, magnetometer, or any of a satellite navigation system (such as GPS, GLONASS, BeiDou Navigation Satellite System, Galileo, compass, etc.). The 3D positioning sensor 138 can be used to determine the vehicle's position on Earth using satellite signals. Sensor 130 may include a camera 140 and / or an IMU (Inertial Measurement Unit) 142. The camera 140 may be a single-frame or stereo camera and capable of recording still and / or video images. The IMU 142 may include multiple gyroscopes and accelerometers capable of detecting the vehicle's linear and rotational motion in three directions. One or more encoders (not shown), such as wheel encoders, may be used to monitor the rotation of one or more wheels of vehicle 110A. Each sensor 130 is capable of outputting sensor data at various data rates, which may differ from the data rates of other sensors 130.

[0152] 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. The positioning subsystem 152 is capable of functions such as accurately determining the position and orientation (sometimes referred to as "pose") of vehicle 110A in its surrounding environment, typically within a reference frame. As part of generating labeled autonomous vehicle data, the position of the autonomous vehicle can be compared with the positions of additional vehicles in the same environment. The perception subsystem 154 is capable of functions such as detecting, tracking, identifying, and / or recognizing objects in the environment surrounding vehicle 110A. Machine learning models can be used to track objects. The planning subsystem 156 is capable of functions such as planning a trajectory for vehicle 110A within a time frame, given a desired destination and static and moving objects within the environment. Machine learning can be used to plan vehicle trajectories. The control subsystem 158 is capable of functions such as generating appropriate control signals to control various controls in the vehicle control system 120 to achieve the planned trajectory of vehicle 110A. It can use machine learning models to generate one or more signals to control autonomous vehicles to implement planned trajectories.

[0153] It should be understood that Figure 1A The assembly of components in 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, sensors may be used... Figure 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 should be understood that in some embodiments, some or all of the functionality of subsystems 152-158 can be implemented using 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, in some cases, be implemented using the same processor and / or memory. Subsystems can be implemented, at least in part, using various special-purpose circuit logics, various processors, various field-programmable gate arrays (“FPGAs”), various application-specific integrated circuits (“ASICs”), various real-time controllers, etc., and as mentioned above, multiple subsystems can utilize circuit systems, processors, sensors, and / or other components. Furthermore, the various components in the vehicle control system 120 can be networked in various ways.

[0154] In some embodiments, vehicle 110A may further include an auxiliary vehicle control system (not shown), which can serve as a redundancy or backup control system for vehicle 110A. The auxiliary vehicle control system is capable of fully operating the autonomous vehicle 110A in the event of an adverse event in vehicle control system 120. In other embodiments, the auxiliary vehicle control system may have only limited functionality, such as controlled stopping 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.

[0155] Generally speaking, countless different architectures can be used to implement this. Figure 1A The various components shown represent numerous different architectures, including various combinations of software, hardware, circuit logic, sensors, networks, etc. For example, each processor can be implemented as a microprocessor, and each memory can represent a random access memory (“RAM”) device, including main memory and any supplementary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), read-only memory, etc. Furthermore, each memory can be considered to include memory storage physically located elsewhere in the vehicle 110A, such as any cache memory within the processor, and any storage capacity used as virtual memory, such as storage on a mass storage device or another computer controller. Figure 1A One or more processors, or completely independent processors, shown can be used in vehicle 110A to implement additional functionality beyond autonomous control purposes, such as controlling the entertainment system, operating doors, lights, convenience features, etc.

[0156] In addition, for additional storage, the vehicle 110A may include one or more mass storage devices, such as removable disk drives, hard disk drives, direct access storage devices (“DASD”), optical disc drives (e.g., CD drives, DVD drives, etc.), solid-state storage drives (“SSD”), network attached storage, storage area networks, and / or tape drives, etc.

[0157] In addition, vehicle 110A may include user interface 164 to enable vehicle 110A to receive multiple inputs from a user or operator and generate outputs for the user or operator, such as one or more displays, touchscreens, voice and / or gesture interfaces, buttons, and other tactile controls. Alternatively, user input may be received via another computer or electronic device, such as via an application on a mobile device or via a web interface.

[0158] Furthermore, vehicle 110A may include one or more network interfaces, such as network interface 162, adapted to communicate with one or more networks 170 (e.g., local area network (“LAN”), wide area network (“WAN”), wireless network, and / or the Internet, etc.) to allow communication of information with other computers and electronic devices, including, for example, a central service such as a cloud service, from which vehicle 110A receives environmental and other data for its autonomous control. Data collected by one or more sensors 130 can be uploaded via network 170 to computing system 172 for ancillary processing. A timestamp can be added to each instance of vehicle data before uploading.

[0159] Figure 1A Each processor shown, as well as the various additional controllers and subsystems disclosed herein, typically operates under the control of an operating system and executes or otherwise depends on various computer software applications, components, programs, objects, modules, data structures, etc., as will be described in more detail below. Furthermore, the various applications, components, programs, objects, modules, etc., can also execute on one or more processors in another computer coupled to vehicle 110A via network 170, for example, in a distributed, cloud-based, or client-server computing environment, thereby distributing the processing required to implement the functions of the computer program to multiple computers and / or services on the network.

[0160] Generally, routines executed to implement the various embodiments described herein, whether as part of an operating system or as a particular application, component, program, object, module, or sequence of instructions, or even a subset thereof, are referred to herein as "program code." Program code can include one or more instructions that reside at different times in various memories and storage devices, and when read and executed by one or more processors, perform the steps or elements necessary to embody the aspects of this disclosure. Furthermore, while embodiments have been described and will be described below in the context of fully functional computer and systems, it should be understood that the various embodiments described herein can be distributed as program products in various forms, and can be implemented regardless of the specific type of computer-readable medium used for actual distribution.

[0161] Examples of computer-readable media include tangible, non-transitory media—such as volatile and non-volatile memory devices, floppy disks and other removable disks, solid-state drives, hard disk drives, magnetic tapes and optical discs (e.g., CD-ROMs, DVDs, etc.), and so on.

[0162] Furthermore, the various program codes described below can be identified according to their application in a particular implementation. However, it should be understood that any particular program nomenclature used below is for convenience only, and therefore this disclosure should not be limited to use only in any particular application identified and / or implied by that nomenclature. Moreover, given the virtually 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 (e.g., operating systems, libraries, APIs, applications, applets, etc.) residing in a typical computer, it should be understood that this disclosure is not limited to the specific organization and distribution of program functionality described herein.

[0163] Figure 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.

[0164] 2. FM LIDAR for automotive applications

[0165] Trucks can include LIDAR systems (e.g., Figure 1A The vehicle control system 120 in Figure 2 (e.g., LIDAR system 200). In some embodiments, a LIDAR system can use frequency modulation to encode an optical signal and use optics to scatter the encoded optical signal into free space. By detecting the frequency difference between the encoded optical signal and the reflected signal from the object, a frequency-modulated (FM) LIDAR system can determine the position of the object and / or accurately measure the velocity of the object using the Doppler effect. FM LIDAR systems can use continuous wave (referred to as "FMCW LIDAR" or "coherent FMCW LIDAR") or quasi-continuous wave (referred to as "FMQW LIDAR"). A LIDAR system can use phase modulation (PM) to encode an optical signal and use optics to scatter the encoded optical signal into free space.

[0166] FM or phase-modulated (PM) LiDAR systems may offer significant advantages over traditional LiDAR systems in automotive and / or commercial truck applications. Firstly, in some cases, objects (e.g., pedestrians wearing dark clothing) may have low reflectivity, reflecting only a small amount of light (e.g., 10% or less) back to the sensor of an FM or PM LiDAR system. Figure 1A (Sensor 130 in the system). In other cases, an object (e.g., a flashing road sign) may have a high reflectivity (e.g., above 10%) because it reflects a large amount of light that hits the object back to the sensor of the FM LIDAR system.

[0167] Regardless of an object's reflectivity, FM LIDAR systems are able to detect (e.g., classify, identify, discover) objects at much greater distances (e.g., twice as far) than traditional LIDAR systems. For example, an FM LIDAR system can detect low-reflectivity objects at distances of more than 300 meters and high-reflectivity objects at distances of more than 400 meters.

[0168] To achieve this improvement in detection capability, the FM LIDAR system can use sensors (e.g., Figure 1A (Sensor 130 in the example). In some implementations, these sensors can be single-photon sensitive, meaning they can detect the smallest possible amount of light. While FM LIDAR systems can use infrared wavelengths (e.g., 950 nm, 1550 nm, etc.) in some applications, they are not limited to the infrared wavelength range (e.g., near-infrared: 800 nm–1500 nm; mid-infrared: 1500 nm–5600 nm; and far-infrared: 5600 nm–1,000,000 nm). By operating FM or PM LIDAR systems at infrared wavelengths, FM or PMLIDAR systems can broadcast stronger light pulses or beams while meeting eye safety standards. Conventional LIDAR systems are typically insensitive to single photons and / or operate only at near-infrared wavelengths, thus requiring them to limit their light output (and distance detection capabilities) for eye safety reasons.

[0169] Therefore, by detecting objects at greater distances, FM LIDAR systems can have more time to react to unexpected obstacles. In fact, even a few extra milliseconds can improve safety and comfort, especially for heavy vehicles (e.g., commercial trucks) driven at highway speeds.

[0170] Another advantage of FM LIDAR systems is their ability to provide accurate velocity for each data point in real time. In some implementations, velocity measurement is achieved using the Doppler effect, which offsets the frequency of light received from an object based on at least one of radial velocity (e.g., the direction vector between the detected object and the sensor) or the frequency of the laser signal. For example, for a velocity encountered on a road condition with a speed less than 100 m / s, such an offset at a wavelength of 1550 nanometers (nm) corresponds to a frequency offset of less than 130 MHz. This frequency offset is very 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, allowing the frequency offset to be calculated using various signal processing techniques. This enables autonomous vehicle control systems to process incoming data much faster.

[0171] 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, FM LIDAR sensors (e.g., Figure 1A The sensor 130 in the system may only receive a few returns from objects at a distance of 300 meters (e.g., hits), but if these returns give a velocity value of interest (e.g., moving toward the vehicle at a speed >70 mph), the FM LIDAR system and / or the autonomous vehicle control system can determine the appropriate weights of the probabilities associated with the object.

[0172] The faster the FM LIDAR system identifies and / or tracks an object, the more time the autonomous vehicle control system has to maneuver the vehicle. A better understanding of the object's speed also allows the autonomous vehicle control system to plan better responses.

[0173] Another advantage of FM LIDAR systems is that they experience less electrostatic interference compared to traditional LIDAR systems. That is, traditional LIDAR systems, designed to be more sensitive to light, typically perform poorly in bright sunlight. These systems are also susceptible to crosstalk (e.g., when sensors are confused by each other's light pulses or beams) and self-interference (e.g., when a sensor is confused by its own preceding light pulse or beam). To overcome these drawbacks, vehicles using traditional LIDAR systems typically require additional hardware, complex software, and / or more computing power to manage this "noise."

[0174] In contrast, FM LIDAR systems do not suffer from such problems because each sensor is specifically designed to respond only to its own optical characteristics (e.g., beams, light waves, light pulses). If the returned light does not match the time, frequency, and / or wavelength of the original transmission, the FM sensor can filter (e.g., delete, ignore, etc.) that data point. Therefore, FM LIDAR systems produce (e.g., generate, export, etc.) more accurate data and have lower hardware or software requirements, resulting in safer and smoother driving.

[0175] Finally, FM LIDAR systems are more scalable than traditional LIDAR systems. As more autonomous vehicles (e.g., cars, commercial trucks, etc.) appear on the road, vehicles powered by FM LIDAR systems may not have to deal with interference issues caused by sensor crosstalk. Furthermore, FM LIDAR systems use lower peak power light than traditional LIDAR sensors. Therefore, some or all of the optical components of an FM LIDAR can be manufactured on a single chip, which has its own advantages, as described in this article.

[0176] 3. Commercial trucks

[0177] Figure 1BThis is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some embodiments. Environment 100B includes a commercial truck 102B for hauling cargo 106B. In some embodiments, the commercial truck 102B may include a vehicle configured for long-haul freight, regional freight, intermodal freight (i.e., where a road-based vehicle is used as one of a variety of modes of transport to move cargo), and / or any other road-based freight application. The commercial truck 102B may be a flatbed truck, a refrigerated truck (e.g., a refrigerated box truck), a ventilated van (e.g., a dry van), a mobile truck, etc. Cargo 106B may be goods and / or products. The commercial truck 102B may include trailers for carrying cargo 106B, such as flatbed trailers, low-floor trailers, ladder trailers, retractable flatbed trailers, side trailers, etc.

[0178] Environment 100B includes object 110B (in Figure 1B (The vehicle shown in the image is another vehicle), and its distance from the truck is equal to or less than 30 meters.

[0179] Commercial truck 102B may include LIDAR system 104B (e.g., FM LIDAR system, Figure 1A The vehicle control system 120 (etc.) is used to determine the distance to object 110B and / or measure the speed of object 110B. Although Figure 1B A LIDAR system 104B is shown mounted on the front of a commercial truck 102B, but the number of LIDAR systems and the mounting areas of the LIDAR systems on the commercial truck are not limited to a specific number or specific area. The commercial truck 102B may include any number of LIDAR systems 104B (or components thereof, such as sensors, modulators, coherent signal generators, etc.) mounted in any area of ​​the commercial truck 102B (e.g., front, rear, side, top, bottom, under, and / or bottom) to facilitate the detection of objects in any free space relative to the commercial truck 102B.

[0180] As shown in the figure, the LIDAR system 104B in environment 100B can be configured to detect objects (e.g., another vehicle, bicycle, tree, street sign, pothole, etc.) at close range (e.g., 30 meters or less) to commercial truck 102B.

[0181] Figure 1C This is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some embodiments. Environment 100C includes the same components contained in environment 100B (e.g., commercial truck 102B, cargo 106B, LIDAR system 104B, etc.).

[0182] Environment 100C includes object 110C (in) Figure 1CAs shown in the figure, the object 110C is located within a distance range of (i) greater than 30 meters and (ii) equal to or less than 150 meters from the commercial truck 102B. The LIDAR system 104B in environment 100C can be configured to detect objects (e.g., another vehicle, bicycle, tree, road sign, pothole, etc.) at a distance (e.g., 100 meters) from the commercial truck 102B.

[0183] Figure 1D This is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some embodiments. Environment 100D includes the same components contained in Environment 100B (e.g., commercial truck 102B, cargo 106B, LIDAR system 104B, etc.).

[0184] Environment 100D includes object 110D (in Figure 1D As shown in the figure, the object 110D is located at a distance greater than 150 meters from the commercial truck 102B (displayed as another vehicle). As shown in the figure, the LIDAR system 104B in the environment 100D can be configured to detect objects (e.g., another vehicle, bicycle, tree, road sign, pothole, etc.) at a certain distance (e.g., 300 meters) from the commercial truck 102B.

[0185] In commercial truck applications, due to increased weight and the resulting need for longer stopping distances, effective detection of objects across the entire range is crucial. Because of these advantages, FM LIDAR systems (e.g., FMCW and / or FMQW systems) or PM LIDAR systems are well-suited for commercial truck applications. Therefore, commercial trucks equipped with such systems can enhance their ability to safely transport people and goods over short or long distances, thereby improving not only the safety of the commercial truck itself 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 some functions of the commercial truck are operated autonomously using the FM or PM LIDAR system, or in fully autonomous applications where the commercial truck is operated entirely by the FM or LIDAR system alone or in combination with other vehicle systems.

[0186] 4. Continuous wave modulation and quasi-continuous wave modulation

[0187] In a LiDAR system using CW modulation, the modulator continuously modulates the laser. For example, if the modulation period is 10 seconds, the input signal is modulated throughout the entire 10 seconds. Conversely, in a LiDAR system using quasi-CW modulation, the modulator modulates the laser to have both an active and an inactive portion. For example, for a 10-second period, the modulator modulates the laser for only 8 seconds (sometimes called the "active portion"), but not for 2 seconds (sometimes called the "inactive portion"). By doing so, the LiDAR system can reduce power consumption by 2 seconds because the modulator does not have to provide a continuous signal.

[0188] In frequency modulated continuous wave (FMCW) LiDARs used in automotive applications, it can be advantageous to operate the LiDAR system using quasi-continuous wave modulation, where FMCW measurement and signal processing methods are employed, but the optical signal is not always on (e.g., enabled, powered on, transmitted, etc.). In some implementations, the duty cycle of the quasi-continuous wave modulation can be equal to or greater than 1% and can be as high as 50%. If the energy that is in the off state (e.g., disabled, powered off, etc.) can be consumed during the actual measurement time, the signal-to-noise ratio (SNR) may be improved and / or the signal processing requirements reduced, allowing for the coherent integration of all energy over longer timescales.

[0189] Figure 2 A LiDAR system 200 including a local oscillator module 212 according to an embodiment of the present disclosure is shown. The LiDAR system 200 may be a LiDAR system 104B (such as...). Figure 1B Example implementation (shown). In Figure 2In the illustrated embodiment, the LIDAR system 200 includes a laser 202, a beam splitter 204, a polarization module 206, a local oscillator module 212, a transmit beam module 220, a LIDAR pixel array 214, and processing logic 299. The beam splitter 204 can be coupled to the laser 202 to receive a transmit signal 210. The beam splitter 204 can split the transmit signal 210 into a transmit beam 213 and a local oscillator signal 211. Optionally, a polarization module (such as polarization module 206) can receive the local oscillator signal 211 and generate a first local oscillator signal 224 and a second local oscillator signal 226. The first local oscillator signal 224 and the second local oscillator signal 226 can have different polarization orientations. In the illustrated embodiment, the first local oscillator signal 224 and the second local oscillator signal 226 have orthogonal polarization orientations because the first local oscillator signal 224 is shown as S-polarized light (LOS) and the second local oscillator signal 226 is shown as P-polarized light (LOP). In this embodiment, the first local oscillator signal 224 and the second local oscillator signal 226 have the same polarization orientation. At least one of the first local oscillator signal and the second local oscillator signal can be derived from the local oscillator signal 211.

[0190] Local oscillator module 212 is configured to receive a first local oscillator signal 224 at a first local oscillator input 228 and a second local oscillator signal 226 at a second local oscillator input 229. Local oscillator module 212 is coupled to a plurality of LiDAR pixels in LiDAR pixel array 214. Local oscillator module 212 is configured to selectively provide the first local oscillator signal 224 and the second local oscillator signal 226 to beam-transmitting LiDAR pixels among the plurality of LiDAR pixels.

[0191] In this implementation, the LIDAR pixel array 214 includes eight LIDAR pixels, and at any given time, one of the LIDAR pixels in the LIDAR pixel array 214 is a beam-emitting LIDAR pixel. The beam-emitting LIDAR pixel can also receive a transmit beam via optical bus 222. Processing logic 299 can drive local oscillator module 212 and transmit beam module 220 to provide transmit beam 213, a first local oscillator signal 224, and a second local oscillator signal 226 to the same LIDAR pixel (beam-emitting LIDAR pixel) in the LIDAR pixel array 214. Processing logic 299 can also drive local oscillator module 212 and transmit beam module 220 to sequentially provide transmit beam 213, the first local oscillator signal 224, and the second local oscillator signal 226 to different LIDAR pixels in the LIDAR pixel array 214 to scan each LIDAR pixel that is a beam-emitting LIDAR pixel. In this way, each LiDAR pixel can emit a transmit beam and detect the return beam as the emission of the transmit beam reflected from a target in the environment. Each LiDAR pixel can generate one or more beat frequency signals by detecting the return beam, and the beat frequency signals can be used to form a LiDAR image.

[0192] By providing the transmit beam 213, the first local oscillator signal 224, and the second local oscillator signal 226 to the same LIDAR pixels (instead of providing these signals to all LIDAR pixels simultaneously), the optical power required to operate the LIDAR system 200 is reduced. Another potential advantage is the reduction in optical noise in the LIDAR system 200, which can increase the signal-to-noise ratio (SNR) of the beat frequency signals generated by the LIDAR pixels. This reduction in optical noise, resulting from not providing all optical signals to each LIDAR pixel simultaneously, may stem from, for example, reduced optical crosstalk between waveguides of adjacent LIDAR pixels, and can help reduce the complexity of electrical signal routing. Advantageously, reducing the complexity of electrical signal routing can save on the cost of conductors (e.g., copper), reduce weight, and allow for a smaller LIDAR pixel array size. Particularly for autonomous vehicles, the cost reduction allows for the deployment of LIDAR systems on more vehicles, while the reduction in weight and size allows for more diverse placement of LIDAR pixel arrays on autonomous vehicles.

[0193] Figure 2Optical buses 216, 218, and 222 are shown. Optical bus 216 is coupled between local oscillator module 212 and LIDAR pixel array 214. Optical bus 218 is also coupled between local oscillator module 212 and LIDAR pixel array 214. Optical bus 222 is coupled between transmit beam module 220 and LIDAR pixel array 214. Optical bus 216 (LOS 0-7) may include eight waveguides to provide a first local oscillator signal 224 to the eight LIDAR pixels of LIDAR pixel array 214, and optical bus 218 (LOP 0-7) may include eight waveguides to provide a second local oscillator signal 226 to the eight LIDAR pixels of LIDAR pixel array 214. Similarly, optical bus 222 (TX 0-7) may include eight waveguides to provide transmit beam 213 to the eight LIDAR pixels of LIDAR pixel array 214. As an example, the LIDAR pixel array 214 can include any number of LIDAR pixels, such as 4, 16, 32, 48, 64, 96, or 128 LIDAR pixels. As another example, the LIDAR pixel array 214 can include 3, 9, 28, or 81 LIDAR pixels. As yet another example, the LIDAR pixel array 214 can include 5, 25, or 125 LIDAR pixels. In these examples, different numbers of LIDAR pixels can be selected to achieve the desired loss range.

[0194] Figure 2 Buses 240 and 242 are also shown. Buses 240 (RXS 0-7) and 242 (RXP 0-7) may be electrical buses, rather than optical buses. Buses 240 and 242 may carry beat frequency signals generated by the LIDAR pixels of the LIDAR pixel array 214.

[0195] Figure 3 An example diagram of a LiDAR transceiver 300, which may include a component portion of a LiDAR system 200, is shown according to an embodiment of the present disclosure. According to an embodiment of the present disclosure, the LiDAR transceiver 300 includes a local oscillator module 302 coupled to provide a local oscillator signal to a LiDAR pixel array 304. The local oscillator module 302 may be configured to be the same as or similar to a local oscillator module 212.

[0196] The local oscillator (LO) module 302 can be coupled to one or more of the plurality of input ports 306 via waveguides 310 and 312 to receive one or both of the local oscillator signals LOS and LOP. According to embodiments of this disclosure, the local oscillator module 302 can be configured to provide local oscillator signals LOS and LOP to one or more LIDAR pixels of the LIDAR pixel array 304, enabling the LIDAR pixels to generate receive signals RXS0-7 and RXP0-7 and provide the signals to the plurality of output ports 308.

[0197] LIDAR pixel array 304 may include a plurality of LIDAR pixels positioned along one or two dimensions of the coverage area of ​​LIDAR transceiver 300. LIDAR pixel array 304 may be configured to be the same as or similar to LIDAR pixel array 214. According to an embodiment, LIDAR pixel 314 is an example of one or more LIDAR pixels of LIDAR pixel array 304. According to an embodiment, LIDAR pixel 314 may receive a transmit beam at port 316, a first local oscillator signal (LOS) at port 318, and a second local oscillator signal (LOP) at port 320. Transmit beam module 220 ( Figure 3 (Not shown) The transmit beam can be selectively provided to port 316 via terminal TX7 of LIDAR transceiver 300. According to embodiments of the present disclosure, LIDAR pixel 314 can be configured to generate receive signal RXS and / or receive signal RXP, and one or both of the receive signals RXS and RXP can be provided to ports 322 and 324 respectively.

[0198] LIDAR pixel 314 may include one or more optical antennas. Figure 3An optical antenna array 326, a receiver circuit system 328, and an optical rotator 330 according to embodiments of the present disclosure are illustrated. The optical antenna array 326 may include at least one transmitting optical antenna configured to receive and transmit a transmitted beam into a LIDAR environment. The optical antenna array 326 may include a receiving optical antenna configured to detect a returning beam. The receiving optical antenna may be configured to detect a first polarization orientation and a second polarization orientation of the returning beam. The first polarization orientation may be orthogonal to the second polarization orientation. The receiver circuit system 328 may be configured to convert an optical signal into an electrical signal, such as a received signal RXS and a received signal RXP. The receiver circuit system 328 may include one or more pairs of photodiodes configured to receive light and generate an electrical signal in response to the received light. The optical rotator 330 may be located between the optical antenna array 326 and the receiver circuit system 328. The optical rotator 330 can be configured to provide a transmit signal to the optical antenna array 326 and can be configured to provide a return signal from the return optical antenna to the receiver circuitry 328 to support the generation of the receive signals RXS and RXP.

[0199] LIDAR transceiver 300 may include an array of power monitors configured to detect the amount of power in each transmitted signal provided to the LIDAR pixels of LIDAR pixel array 304. The power monitor array may include one power monitor for each LIDAR pixel of LIDAR pixel array 304. Power monitor 332 may be an example of a power monitor in the power monitor array. Power monitor 332 may include waveguide 334, waveguide 336, and photodiode 338. The transmitted beam can propagate through waveguide 334, so waveguide 334 can be linearly positioned with respect to the transmitted signal waveguide. Waveguide 336 may be located near waveguide 334 to receive a portion of the transmitted signal. Photodiode 338 may be coupled to waveguide 336 and may be configured to convert a portion of the transmitted signal into an electrical signal to support power monitoring operation. Transceiver 300 may include a plurality of ports 340 communicatively coupled to the power monitors of the power monitor array and configured to provide an external power monitor output to transceiver 300. In some implementations, port 340 may be used to provide control signals from processing logic (e.g., processing logic 299) to drive local oscillator module 302.

[0200] According to one embodiment, transceiver 300 receives transmit beams (e.g., TX0, TX1, TX2, TX3, TX4, TX5, TX6, TX7, etc.) at a port 306 coupled to LIDAR pixel array 304 via multiple waveguides (e.g., waveguide 342). Although eight transmit signals (e.g., TX0-7) and 16 receive signals (receive signals RXS0-7 and RXP0-7) are shown, more or fewer transmit and receive signals can be implemented in transceiver 300 according to various embodiments of this disclosure.

[0201] Figure 4 An example local oscillator module 499 according to an embodiment of the present disclosure is shown. The local oscillator module 499 may include a plurality of optical switches, such as optical switches 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, and 413. Each optical switch is controlled by a corresponding control input X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, and X13. For example, the control inputs may be coupled to processing logic 299. Processing logic 299 may drive the optical switches via their respective control inputs to direct a local oscillator signal to a specific LIDAR pixel at a specific time. In an embodiment, processing logic 299 drives the optical switches to direct a local oscillator signal to only one specific LIDAR pixel at a given time. The local oscillator module 499 can be described as a "2 to 2n" distributed network because it is capable of dynamically routing two signals to 2n ports, where n is a number. Figure 4 In one implementation, n is 8, and there are 16 (2n) output ports. In one implementation, the local oscillator module can be a “3 to 3n” distribution network because it is capable of dynamically routing three signals to 3n ports, where n is a number. In another implementation, the local oscillator module can be a “5 to 5n” distribution network because it is capable of dynamically routing five signals to 5n ports, where n is a number. In these implementations, a specific distribution network can be selected to achieve ideal dynamic routing and optimal signal processing.

[0202] exist Figure 4 In this configuration, optical switch 400 is configured to receive a first local oscillator signal LOS 434, and optical switch 401 is configured to receive a second local oscillator signal LOP 436. Figure 4 In the diagram, the dashed line represents the waveguide providing the first local oscillator signal 434, and the solid line represents the waveguide providing the second local oscillator signal 436. Figure 4 Component 441 in the middle represents Figure 4Waveguide crossings in the local oscillator module 499. In some implementations of the local oscillator module 499, multiple waveguide stages are included, so the waveguides do not need to cross each other, therefore the waveguide crossing assembly 441 is not necessary.

[0203] In an implementation, driving a digital high (e.g., 3.3 VDC) to the control input causes the optical switch to guide the input light away from the left output port, while driving a digital low (e.g., 0 VDC) to the control input causes the optical switch to guide the input light away from the right output port. For example, to provide a first local oscillator signal 434 and a second local oscillator signal 436 to the first LIDAR pixel, control inputs X0, X1, X2, X3, X6, and X7 are driven digitally high, such that the first local oscillator signal 434 is directed to port LOS 480S, and the second local oscillator signal 436 is directed to port LOP 480P. To provide the first local oscillator signal 434 and the second local oscillator signal 436 to the second LIDAR pixel, input ports X0, X1, X2, and X3 can be driven digitally high, and input ports X6 and X7 can be driven digitally low, such that the first local oscillator signal 434 is directed to port LOS 481S, and the second local oscillator signal 436 is directed to port LOP 481P. In some embodiments, the signals on control inputs X0, X1, X2, X3, X6, and X7 are analog signals. Processing logic 299 can continue to drive the control inputs of the optical switches to perform raster scanning through the multiple LIDAR pixels to provide the first local oscillator signal 434 and the second local oscillator signal 436 to generate beat frequency signals for the beam-emitting LIDAR pixels. The third, fourth, fifth, sixth, seventh, and eighth LIDAR pixels can receive the first local oscillator signal 434 and the second local oscillator signal 436 through the control ports that drive the optical switches. For example, the third LIDAR pixel can receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 482S and LOP 482P; the fourth LIDAR pixel can receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 483S and LOP 483P; the fifth LIDAR pixel can receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 484S and LOP 484P; the sixth LIDAR pixel can receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 485S and LOP 485P; the seventh LIDAR pixel can receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 486S and LOP 486P; and the eighth LIDAR pixel can receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 487S and LOP 482P. The 487P is used to receive the first local oscillator signal 434 and the second local oscillator signal 436.

[0204] Figure 5An example transmit beam module 599 according to an embodiment of the present disclosure is shown. The transmit beam module 599 may include a plurality of optical switches, such as optical switches 500, 501, 502, 503, 504, 505, and 506. Each optical switch is controlled by a corresponding control input X20, X21, X22, X23, X24, X25, and X26. For example, the control inputs may be coupled to processing logic 299. Processing logic 299 may drive the optical switches via its respective control inputs to direct the transmit beam to a specific LIDAR pixel at a specific time. In an embodiment, processing logic 299 drives the optical switches to direct the transmit beam to only one specific LIDAR pixel at a given time.

[0205] exist Figure 5 In this configuration, optical switch 500 is configured to receive and transmit beam 513. Figure 5 Component 541 in the diagram represents a waveguide crossover. In an implementation, driving a digital high (e.g., 3.3 VDC) to the control input causes the optical switch to guide the input light away from the left output port, while driving a digital low (e.g., 0 VDC) to the control input causes the optical switch to guide the input light away from the right output port. For example, to provide a transmit beam 513 to a first LIDAR pixel, control inputs X20, X21, and X23 are driven digitally high, causing the transmit beam 513 to be guided to port TX 560. To provide a transmit beam 513 to a second LIDAR pixel, input ports X22 and X24 can be driven digitally high, while input port X20 can be driven digitally low, causing the transmit beam 513 to be guided to port TX 561. Processing logic 299 can continue to drive the control inputs of the optical switch to perform a raster scan through multiple LIDAR pixels to provide the transmit beam 513 to generate a beat frequency signal for the beam-emitting LIDAR pixel. The third, fourth, fifth, sixth, seventh, and eighth LIDAR pixels can receive the transmit beam 513 through the control port that drives the optical switch, so as to provide the transmit beam 513 to ports TX 562, TX 563, TX 564, TX 565, TX 566, and TX 567.

[0206] Figure 6 An example LIDAR pixel 699 according to an embodiment of the present disclosure is shown, including a first coherent receiver 621 and a second coherent receiver 626. The LIDAR pixel 699 includes a transmit optical antenna 605, a receive optical antenna 610, a first coherent receiver 621, and a second coherent receiver 626. The transmit optical antenna 605 is configured to transmit a transmit beam. The transmit beam may be an infrared transmit beam. The transmit beam may be a near-infrared transmit beam. The transmit beam may have a single defined polarization orientation. Figure 6In this diagram, the transmitting optical antenna 605 is shown as a single-polarization output coupler and can transmit a transmitting beam in response to receiving a transmitting beam 601 via waveguide 603. The transmitting beam 601 can be generated by a laser, and the transmitting beam emitted by the transmitting optical antenna 605 can have a very narrow linewidth (e.g., 1 nm or less). The transmitting beam 601 can be selectively provided to the transmitting optical antenna 605 by the transmitting beam module 220.

[0207] exist Figure 6 In the illustration, the receiving optical antenna 610 is a dual-polarization receiving optical antenna configured to detect a first polarization orientation and a second polarization orientation of the returned beam. The returned beam is a reflection of the transmitted beam reflected from a target in the external environment of the LIDAR system 600. The first polarization orientation may be orthogonal to the second polarization orientation. The dual-polarization receiving optical antenna 610 is configured to couple the first polarization orientation of the returned beam to a first coherent receiver 621 via waveguide 612, and to couple the second polarization orientation of the returned beam to a second coherent receiver 626 via waveguide 617. In one embodiment, the receiving optical antenna 610 includes a first polarization receiving grating configured to guide the first polarization orientation of the returned beam to the first coherent receiver 621, and a second polarization receiving grating configured to guide the second polarization orientation of the returned beam to the second coherent receiver 626. In another embodiment, the first polarization receiving grating and the second polarization receiving grating are spaced apart.

[0208] The first coherent receiver 621 is configured to generate a first signal 623 in response to receiving a first polarization orientation and a first local oscillator signal 631 of the returned beam. The first local oscillator signal 631 may be an optical signal having a first polarization orientation. For example, the first local oscillator signal 631 may be selectively provided by a local oscillator module 212. Figure 6 In this process, the first coherent receiver 621 receives the first polarization orientation of the returned beam from the first single-polarization grating coupler 611 via waveguide 612, and the first coherent receiver 621 receives the first local oscillator signal 631 via waveguide 632. The first signal 623 may be an electrical signal provided to the processing logic 650 via communication channel 622.

[0209] The second coherent receiver 626 is configured to generate a second signal 628 in response to receiving a second polarization orientation and a second local oscillator signal 636 of the returned beam. The second local oscillator signal 636 may be an optical signal with a second polarization orientation. For example, the second local oscillator signal 636 may be selectively provided by the local oscillator module 212. Figure 6In this process, the second coherent receiver 626 receives the second polarization orientation of the returned beam from the second single-polarization grating coupler 616 via waveguide 617, and the second coherent receiver 626 receives the second local oscillator signal 636 via waveguide 637. The second signal 628 may be an electrical signal provided to the processing logic 650 via communication channel 627.

[0210] Processing logic 650 is configured to generate image 655 in response to receiving a first signal 623 and a second signal 628 from a first coherent receiver 621 and a second coherent receiver 626, respectively. LIDAR system 600 may include a LIDAR pixel array 699 configured to provide the processing logic 650 with the first signal (e.g., signal 623) and the second signal (e.g., signal 628). In this scenario, processing logic 650 may generate image 655 in response to the first and second signals received by processing logic 650 through a plurality of LIDAR pixels 699 in the LIDAR pixel array.

[0211] Figure 7 An example coherent receiver 771 according to an embodiment of the present disclosure is shown. In some embodiments, Figure 7 Example coherent receiver 771 can be used as a first coherent receiver 621 and / or a second coherent receiver 626. Coherent receiver 771 includes an optical mixer 752, a return beam port 754, a local oscillator port 758, and an output port 762. According to an embodiment, optical mixer 752 is configured to combine a return beam signal (RB) with a local oscillator signal (LO) to generate an output signal (OUT). For example, optical mixer 752 can be coupled to receive a return beam signal (RB) from waveguide 612 or waveguide 617, and waveguide 756 provides the return beam signal to optical mixer 752. For example, optical mixer 752 can be coupled to receive a local oscillator signal (LO) from waveguide 632 or 637, and waveguide 760 provides the local oscillator signal (LO) to optical mixer 752. Optical mixer 752 can combine input signals to generate multiple combined output signals OUT1 and OUT2. Output signals OUT1 and OUT2 are provided to a pair of photodiodes (including photodiodes PD1 and PD2) to convert the return beam signal RB and the local oscillator signal LO into output signal OUT. Output signal OUT can be an electrical signal. Output signal OUT can also be a beat frequency signal representing the range and / or velocity of one or more objects in the environment of the LIDAR system. For example, communication channels 622 or 627 can be coupled to output port 762.

[0212] Figure 8A process 800 for operating a LIDAR device according to an embodiment of the present disclosure is illustrated. The order in which some or all of the process blocks appear in process 800 should not be considered limiting. Rather, those skilled in the art who benefit from this disclosure will understand that some process blocks can be executed in multiple orders not shown, or even in parallel.

[0213] In process block 805, a light source (e.g., laser 202) is illuminated to generate a transmit beam. The transmit beam may be near-infrared light.

[0214] In process block 810, the transmit beam is selectively directed to the transmit antenna (e.g., antenna 605) of the beam-transmitting LIDAR pixel among the plurality of LIDAR pixels.

[0215] In process block 815, the first local oscillator signal and the second local oscillator signal are selectively directed to the beam-transmitting LIDAR pixel, while the transmit beam is selectively directed to the beam-transmitting LIDAR pixel.

[0216] In an embodiment of process 800, a first local oscillator signal is selectively directed to a first optical mixer of the beam-emitting LIDAR pixel, and a second local oscillator signal is selectively directed to a second optical mixer of the beam-emitting LIDAR pixel. The first local oscillator signal may have a first polarization orientation, and the second local oscillator signal may have a second polarization orientation different from the first polarization orientation.

[0217] A beam-emitting LIDAR pixel may include a receiving optical antenna to detect a returning beam, and a first optical mixer may be configured to receive a first polarization orientation of the returning beam. A second optical mixer may be configured to receive a second polarization orientation of the returning beam.

[0218] In an implementation, process 800 further includes (i) selectively directing the transmit beam to a second transmit antenna of a second beam-transmitting LIDAR pixel among a plurality of LIDAR pixels, and (ii) selectively directing a first local oscillator signal and a second local oscillator signal to the second beam-transmitting LIDAR pixel, while selectively directing the transmit beam to the second beam-transmitting LIDAR pixel.

[0219] In an implementation of process 800, the transmit beam is not directed to the transmit antenna of the beam-emitting LIDAR pixel, while the transmit beam is directed to the second transmit antenna of the second beam-emitting LIDAR pixel, and the first local oscillator signal and the second local oscillator signal are not directed to the beam-emitting LIDAR pixel, while the first local oscillator signal and the second local oscillator signal are directed to the second beam-emitting LIDAR pixel.

[0220] 5. Additional implementation methods for continuous wave modulation and quasi-continuous wave modulation

[0221] Figure 9 A LIDAR system 1200 according to an embodiment of the present disclosure is shown. The LIDAR system 1200 may be a LIDAR sensor 136 (such as...) Figure 1A (as shown) and LIDAR system 104B (as shown) Figure 1B The example implementation is shown below. According to an embodiment of this disclosure, the LIDAR system 1200 includes a laser 1202, a beam splitter 1204, a polarizer 1206, and a transceiver 1208. The beam splitter 1204 can be coupled to the laser 1202 to receive a transmitted signal 1210. According to an embodiment, the beam splitter 1204 can split the transmitted signal 1210 into transmitted signals TX0-7 and local oscillator signals LO1 and LO2. The beam splitter 1204 can be configured to provide the transmitted signals TX0-7 and the local oscillator signals LO1 and LO2 to the transceiver 1208 at a plurality of input ports 1209. Alternatively, according to embodiments of this disclosure, the beam splitter 1204 may be coupled to the polarizer 1206 and configured to provide a first local oscillator signal 1224 and a second local oscillator signal 1226, the polarizer 1206 converting the first local oscillator signal 1224 and the second local oscillator signal 1226 into an S-polarized local oscillator signal LO1 and a P-polarized local oscillator signal LO2. In one embodiment, the local oscillator signals LO1 and LO2 share the same polarization orientation, but are used in the transceiver 1208 to generate received signals RXS0-7 and RXP0-7 from a receiving optical antenna configured to detect different polarizations.

[0222] In some embodiments, transceiver 1208 may be configured to receive input signals (e.g., transmit signals TX0-7 and local oscillator signals LO1 and LO2) and may be configured to generate output signals (e.g., receive signals RXS0-7 and RXP0-7) in response to the input signals. In one embodiment, for example, transceiver 1208 is configured to operate using a transmit signal TX0 and a local oscillator signal LO1. Transceiver 1208 may include a local oscillator network 1212 and a LIDAR pixel array 1214 configured to support scanning and imaging operations in an autonomous vehicle environment.

[0223] In some implementations, the local oscillator network 1212 may be configured to receive one or both of local oscillator signals LO1 and LO2, and may be configured to distribute one or both of local oscillator signals LO1 and LO2 on a first local oscillator bus 1216 and a second local oscillator bus 1218. The first local oscillator bus 1216 and the second local oscillator bus 1218 may include multiple waveguide channels coupled to provide local oscillator signals LO1 and LO2 to the LIDAR pixel array 1214. The local oscillator network 1212 may be coupled to the LIDAR pixel array 1214 via one or both of the local oscillator buses 1216 and 1218.

[0224] For example, the LIDAR pixel array 1214 may include a plurality of LIDAR pixels, each of which may be configured to transmit a transmit beam and detect a return beam in response to a transmit signal TX0-7 and local oscillator signals LO1 and LO2. The LIDAR pixel array 1214 may be configured to generate a plurality of receive signals RXS0-7 from the return beam having a first polarization. The LIDAR pixel array 1214 may be configured to generate a receive signal RXP0-7 from the return beam having a second polarization orientation. The LIDAR pixel array 1214 may provide the receive signal RXS0-7 on a first return signal bus 1220 and may provide the receive signal RXP0-7 on a second return signal bus 1222. The transceiver 1208 may be configured to provide the receive signals RXS0-7 and RXP0-7 to a plurality of output ports 1228. According to embodiments of the present disclosure, the receive signals RXS0-7 and RXP0-7 may be used by processing logic to generate image data and / or images representing objects in the LIDAR operating environment.

[0225] Although transceiver 1208 is described as having eight transmit signals and 16 receive signals, it should be understood that, according to various embodiments of this disclosure, fewer (e.g., one or two) or more (e.g., hundreds or thousands) transmit or receive signals may be used.

[0226] Figure 10A An example of a simplified schematic diagram of a LIDAR transceiver 1300 according to an embodiment of the present disclosure is shown. According to an embodiment of the present disclosure, the LIDAR transceiver 1300 includes a local oscillator network 1302 coupled to provide a local oscillator signal to a LIDAR pixel array 1304.

[0227] In some embodiments, the local oscillator (LO) network 1302 may be coupled to one or more of a plurality of input ports 1306 via waveguides 1310 and 1312 to receive one or both of local oscillator signals LO1 and LO2. According to embodiments of this disclosure, the local oscillator network 1302 may be configured to provide local oscillator signals LO1 and LO2 to one or more LIDAR pixels of the LIDAR pixel array 1304, enabling the LIDAR pixels to generate receive signals RXS0-7 and RXP0-7 and provide the signals to a plurality of output ports 1308.

[0228] In some embodiments, the LIDAR pixel array 1304 may include a plurality of LIDAR pixels positioned along one or two dimensions of the coverage area of ​​the LIDAR transceiver 1300. According to an embodiment, LIDAR pixel 1314 is an example of one or more LIDAR pixels in the LIDAR pixel array 1304. According to an embodiment, LIDAR pixel 1314 may receive a transmit signal at port 1316, a local oscillator signal LO1 at port 1318, and a local oscillator signal LO2 at port 1320. According to embodiments of this disclosure, LIDAR pixel 1314 may be configured to generate a receive signal RXS and / or a receive signal RXP, and may provide one or both of the receive signals RXS and RXP to ports 1322 and 1324, respectively. In an embodiment, LIDAR pixel 1314 receives a transmit signal, receives a local oscillator signal, and provides a single receive signal.

[0229] According to embodiments of this disclosure, the LIDAR pixel 1314 may include an optical antenna array 1326, a receiver circuitry system 1328, and an optical rotator 1330. The optical antenna array 1326 may include at least one transmitting optical antenna configured to receive a transmitted signal and transmit a transmitted beam into the LIDAR environment. The optical antenna array 1326 may include a first receiving optical antenna configured to detect a first polarization orientation of the returned beam, and may include a second receiving optical antenna configured to detect a second polarization orientation of the returned beam, or may include both the first and second receiving optical antennas. The first polarization orientation may be orthogonal to the second polarization orientation. The receiver circuitry system 1328 may be configured to convert optical signals into electrical signals, such as a received signal RXS and a received signal RXP. The receiver circuitry system 1328 may include one or more pairs of photodiodes configured to receive light and generate electrical signals in response to the received light. The optical rotator 1330 may be located between the optical antenna array 1326 and the receiver circuitry system 1328. The optical rotator 1330 can be configured to provide a transmit signal to the optical antenna array 1326 and can be configured to provide a return signal from the returning optical antenna to the receiver circuitry 1328 to support the generation of the received signals RXS and RXP. The optical rotator 1330 can be implemented as a polarization beam splitter within a waveguide, but it is configured to operate as a rotator to provide a transmit signal to the transmit antenna and a receive signal to the receiver circuitry (e.g., an optical mixer and / or a photodiode).

[0230] In some implementations, the LIDAR transceiver 1300 may include an array of power monitors configured to detect the amount of power in each transmitted signal provided to the LIDAR pixels of the LIDAR pixel array 1304. The power monitor array may include one power monitor for each LIDAR pixel in the LIDAR pixel array 1304. Power monitor 1332 may be an example of a power monitor in the power monitor array. Power monitor 1332 may include waveguide 1334, waveguide 1336, and photodiode 1338. The transmitted signal can propagate through waveguide 1334, and therefore waveguide 1334 may be linearly positioned relative to the transmitted signal waveguide. Waveguide 1336 may be located near waveguide 1334 to receive a portion of the transmitted signal. Photodiode 1338 may be coupled to waveguide 1336 and may be configured to convert a portion of the transmitted signal into an electrical signal to support power monitoring operation. The LIDAR transceiver 1300 may include multiple output ports 1340 that are communicatively coupled to the power monitors of the power monitor array and configured to provide power monitor outputs to the outside of the LIDAR transceiver 1300.

[0231] According to various embodiments, the LIDAR transceiver 1300 receives transmit signals (e.g., TX0, TX1, TX2, TX3, TX4, TX5, TX6, TX7, etc.) at some of the ports of port 1306 coupled to the LIDAR pixel array 1304 via multiple waveguides (e.g., waveguide 1342). Although eight transmit signals (e.g., TX0-7) and 16 receive signals (receive signals RXS0-7 and RXP0-7) are shown, more or fewer transmit and receive signals can be implemented in the LIDAR transceiver 1300 according to various embodiments of this disclosure.

[0232] Figure 10B A LIDAR transceiver 1350 according to an embodiment of the present disclosure is illustrated. The LIDAR transceiver 1350 may include beam splitters 1352 and 1354 configured to distribute a transmit signal from an input port 1306. Beam splitters 1352 and 1354 may be implemented as passive beam splitters comprising a plurality of optical beam splitters configured to receive an optical signal and split that optical signal into several output ports (e.g., four ports) to support the operation of the LIDAR pixels of the LIDAR pixel array 1304. According to various embodiments, beam splitters 1352 and 1354 may be one to four beam splitters, or may be configured to split the transmit signal into many more signals (e.g., 8, 16, 32, 64, etc.). Using beam splitters 1352 and 1354 can reduce noise caused by crosstalk and can alleviate the burden associated with the routing waveguides within the LIDAR transceiver 1350.

[0233] Figure 11 A LiDAR system 1400 including LiDAR pixel 1499 according to an embodiment of the present disclosure is shown. LiDAR pixel 1499 may include optical antenna array 1460, which may be optical antenna array 1326 (e.g., Figure 10A and 10B The embodiment shown is illustrated. The optical antenna array 1460 may include a transmitting optical antenna 1405, a receiving optical antenna 1410, a first coherent receiver 1421, and a second coherent receiver 1426. However, the present invention is not limited to this. Figure 11The specific LIDAR pixel architecture shown is applicable. LIDAR pixels can be implemented using any suitable chip design architecture. For example, the transmitting and receiving optical antennas can be implemented as a single module or a single integrated chip, or as separate modules or chips. As another example, the first and second coherent receivers can be implemented as a single module or a single integrated chip, or as separate modules or chips. The transmitting optical antenna 1405 can be configured to transmit a transmit beam. The transmit beam can be an infrared transmit beam. The transmit beam can be a near-infrared transmit beam. The transmit beam can have a single defined polarization orientation. According to the implementation, in Figure 11 In the diagram, the transmitting optical antenna 1405 is shown as a single-polarization output coupler and can transmit a transmit beam in response to receiving a transmit signal 1401 through waveguide 1403. The transmit signal 1401 can be generated by a laser, and the transmit beam emitted by the transmitting optical antenna 1405 can have a very narrow linewidth (e.g., 1 nm or less).

[0234] In some embodiments, the receiving optical antenna 1410 can be a dual-polarization receiving optical antenna configured to detect a first polarization orientation and a second polarization orientation of the returned beam. The returned beam can be a reflection of the transmitted beam reflected from an object in the external environment of the LIDAR system 1400. The first polarization orientation can be orthogonal to the second polarization orientation. In some embodiments, the orthogonality can have a margin greater than 0 to 10%. For example, if the first polarization orientation has an angle between 80 and 100 degrees relative to the second polarization orientation, it can be defined as orthogonal. The first polarization orientation can be s-polarized, while the second polarization orientation can be p-polarized, or vice versa. Figure 11 In the receiving optical antenna 1410, a first single-polarization grating coupler 1411 and a second single-polarization grating coupler 1416 are included. The first single-polarization grating coupler 1411 can be configured to couple a first polarization orientation of the returned beam to a first coherent receiver 1421 via a waveguide 1412. The second single-polarization grating coupler 1416 can be configured to couple a second polarization orientation of the returned beam to a second coherent receiver 1426 via a waveguide 1417. The transmitting optical antenna 1405 can transmit a transmit beam with a second polarization orientation (as shown in the figure), or it can be configured to transmit a transmit beam with a first polarization orientation.

[0235] The first single-polarization grating coupler 1411 can rotate relative to the second single-polarization grating coupler 1416. Figure 11In the specific embodiment shown, the first single-polarization grating coupler 1411 is rotated 90 degrees relative to the second single-polarization grating coupler 1416. The illustrated single-polarization output coupler of the transmitting optical antenna 1405 can be rotated relative to the first single-polarization grating coupler 1411 and can include an orientation similar to that of the second single-polarization grating coupler 1416. Specifically, according to the embodiment, the first single-polarization grating coupler 1411 can be rotated +45 degrees, the transmitting optical antenna 1405 can be rotated -45 degrees, and the second single-polarization grating coupler 1416 can be rotated -45 degrees.

[0236] In some embodiments, the transmitting optical antenna 1405, the first single-polarization grating coupler 1411, and the second single-polarization grating coupler 1416 can be arranged in a one-dimensional (1D) straight line to support receiving return beams (e.g., from rotating mirrors) that may affect the optical antenna array 1460 at positions offset from the transmitting optical antenna 1405, for example, due to the transmit-receive property of using rotating mirrors to transmit and receive LIDAR signals. For example, the first single-polarization grating coupler 1411 can be offset from the transmitting optical antenna 1405 by a distance D1, and the second single-polarization grating coupler 1416 can be positioned between the first single-polarization grating coupler 1411 and the transmitting optical antenna 1405. The second single-polarization grating coupler 1416 can be offset from the transmitting optical antenna 1405 by a second distance D2 within the optical antenna array 1460. The first single-polarization grating coupler 1411 can be offset from the second single-polarization grating coupler 1416 by a third distance D3.

[0237] In some embodiments, the first coherent receiver 1421 may be configured to generate a first signal 1423 in response to receiving a first polarization orientation and a first local oscillator signal 1431 of the returned beam. The first local oscillator signal 1431 may be an optical signal with a first polarization orientation and may be a local oscillator signal LO1. Figure 11 In the first coherent receiver 1421, the first polarization orientation of the returned beam can be received from the first single polarization grating coupler 1411 via waveguide 1412, and the first local oscillator signal 1431 can be received by the first coherent receiver 1421 via waveguide 432. The first signal 1423 can be an electrical signal provided to the processing logic 1450 via communication channel 1422.

[0238] In some embodiments, the first coherent receiver 1421 may include an optical mixer 1462 and a photodiode pair 1464 for converting the received optical signal into an electrical signal. The optical mixer 1462 may be coupled to receive a local oscillator signal LO1 and a signal representing a first polarization orientation of the returned beam from the first single-polarization grating coupler 1411. The optical mixer 1462 may be coupled to the photodiode pair 1464 to provide a mixed output signal. The photodiode pair 1464 may be configured to generate a first signal 1423 and provide the first signal 1423 to the processing logic 1450 via a communication channel 1422. The first signal 1423 may be an example of a received signal RXS (e.g., such as...). Figure 10A and 10B (As shown). The number of output signals of an optical mixer can be any suitable number, and is not limited to a specific number.

[0239] In some embodiments, the second coherent receiver 1426 can be configured to generate a second signal 1428 in response to a second polarization orientation and a second local oscillator signal 1436 received from the returned beam. The second local oscillator signal 1436 can be an optical signal with a second polarization orientation and can be a local oscillator signal LO2. Figure 11 In this process, the second coherent receiver 1426 can receive the second polarization orientation of the returned beam from the second single-polarization grating coupler 1416 via waveguide 1417, and the second coherent receiver 1426 can receive the second local oscillator signal 1436 via waveguide 1437. The second signal 1428 may be an electrical signal provided to the processing logic 1450 via communication channel 1427.

[0240] In some embodiments, the second coherent receiver 1426 may include an optical mixer 1466 and a photodiode pair 1468 for converting the received optical signal into an electrical signal. The optical mixer 1466 may be coupled to receive a local oscillator signal LO2 and a signal representing a second polarization orientation of the returned beam from the second single-polarization grating coupler 1416. The optical mixer 1466 may be coupled to the photodiode pair 1468 to provide a mixed output signal. The photodiode pair 1468 may be configured to generate a second signal 1428 and provide the second signal 1428 to processing logic 1450 via a communication channel 1427. The second signal 1428 may be an example of a received signal RXP (e.g., such as...). Figure 10A and 10B (As shown). The number of output signals of an optical mixer can be any suitable number, and is not limited to a specific number.

[0241] In some embodiments, the received optical signal, the transmitted signal (before transmission), and the local oscillator signal may have the same polarization orientation when on the chip (e.g., when propagating through a waveguide). One or more of the optical antennas may be configured to change the polarization orientation (e.g., rotation) of the return beam and the transmitted beam to one or more specific polarization orientations. For example, the optical antenna may be configured to convert a return beam with a first polarization orientation into the waveguide as a return signal with a second or third polarization orientation. As another example, the transmitted signal may have a third polarization orientation when in the waveguide, and the optical antenna may be configured to couple the transmitted signal into free space as a transmitted beam with a first or second polarization orientation.

[0242] Processing logic 1450 can be configured to generate image 1455 in response to receiving a first signal 1423 and a second signal 1428 from a first coherent receiver 1421 and a second coherent receiver 1426, respectively. LIDAR system 1400 may include a LIDAR pixel array 1499 configured to provide the processing logic 1450 with the first signal (e.g., signal 1423) and the second signal (e.g., signal 1428). In this scenario, processing logic 1450 can generate image 1455 in response to the first and second signals received by processing logic 1450 through a plurality of LIDAR pixels 1499 in the LIDAR pixel array.

[0243] In the operational example, the transmit signal 1401 can be emitted into free space as a transmit beam by the transmit optical antenna 1405. The transmit beam can pass through one or more lenses and be deflected by a rotating mirror, then pass through the external environment until it encounters an object. A portion of the transmit beam that encounters the object can be reflected as a return beam toward the LIDAR system 1400 and LIDAR pixels 1499. The return beam can be reflected from the rotating mirror and pass through one or more lenses, but is offset relative to the transmit optical antenna 1405 due to the time difference of the mirror's rotation. To compensate for this offset, components of the receive optical antenna 1410 can be offset relative to the transmit optical antenna 1405.

[0244] Figure 12A and 12B A simplified block diagram of a LiDAR device with a stacked antenna configuration according to an embodiment of the present disclosure is shown. Figure 12A An example of a LIDAR device 1500 with a first semiconductor layer 1502 stacked on top of a second semiconductor layer 1504 is shown. The LIDAR device 1500 may include a transmit optical antenna 1506 and a receive optical antenna 1508. The transmit optical antenna 1506 is a transmit optical antenna 1405 (e.g., ...). Figure 11The example implementation shown can be configured to transmit a transmit beam with a second polarization orientation. The receiving optical antenna 1508 can be a second single-polarization grating coupler 1416 (e.g., Figure 11 The example implementation shown can be configured to detect a returning beam with a second polarization orientation. The second semiconductor layer 1504 includes a second receiving optical antenna 1510, which may be a first single-polarization grating coupler 1411 (as shown). Figure 11 The example embodiment shown can be configured to detect a returning beam with a first polarization orientation. The receiving optical antenna 1508 can offset the transmitting optical antenna 1506 and can be positioned within a first semiconductor layer stacked on top of the second semiconductor layer. The first semiconductor layer 1502 can be an alloy formed of one or more elements from Group III or Group V of the periodic table. The second semiconductor layer 1504 can be formed of a silicon substrate or a nitride.

[0245] Figure 12B An example of a LiDAR device 1550 according to an embodiment of the present disclosure is shown, having a first semiconductor layer 1552 stacked on top of a second semiconductor layer 1554 and configured to provide stacked optical antenna LiDAR operation. According to an embodiment of the present disclosure, the first semiconductor layer 1552 may include a transmit optical antenna 1506, and the second semiconductor layer 1554 may include a receive optical antenna 1508 and a receive optical antenna 1510, which are offset from each other and positioned to receive the LiDAR return beam passing through the first semiconductor layer 1552.

[0246] The term "processing logic" as used in this disclosure (e.g., processing logic 299 or processing logic 650) may include one or more processors, microprocessors, multi-core processors, application-specific integrated circuits (ASICs), and / or field-programmable gate arrays (FPGAs) to perform the operations disclosed herein. In some embodiments, memory (not shown) is integrated into the processing logic to store instructions for performing operations and / or store data. The processing logic may also include analog or digital circuit systems to perform operations according to embodiments of this disclosure.

[0247] The term "memory" or "multiple memories" described in this disclosure may include one or more volatile or non-volatile memory architectures. "Memory" or "multiple memories" may be removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Example memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile optical disc (DVD), high-definition multimedia / data storage disc, or other optical storage, magnetic tape cassette, magnetic tape, disk storage, or other magnetic storage devices, or any other non-transfer medium capable of storing information for access by a computing device.

[0248] A network may include any network or network system, such as, but not limited to, the following: peer-to-peer networks; local area networks (LANs); wide area networks (WANs); public networks, such as the Internet; private networks; cellular networks; wireless networks; wired networks; combined wireless and wired networks; and satellite networks.

[0249] Communication channels may include or be routed using one or more of the following wired or wireless communications: IEEE 802.11 protocol, Bluetooth, SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit), USB (Universal Serial Port), CAN (Controller Area Network), cellular data protocols (e.g., 3G, 4G, LTE, 5G), optical communication networks, Internet Service Providers (ISPs), peer-to-peer networks, local area networks (LANs), wide area networks (WANs), public networks (e.g., the "Internet"), private networks, satellite networks, or other means.

[0250] Computing devices may include desktop computers, laptop computers, tablet computers, phablets, smartphones, feature phones, server computers, or other devices. Server computers may be located in remote data centers or stored locally.

[0251] The above processes are described in the form of computer software and hardware. The techniques may constitute machine-executable instructions contained in a tangible or non-transitory machine-readable storage medium, which, when executed by a machine, will cause the machine to perform the described operations. Additionally, the processes may be contained within hardware, such as an application-specific integrated circuit (“ASIC”) or other hardware.

[0252] Tangible, non-transitory machine-readable storage media include any mechanism that provides (i.e., stores) information in a form accessible to a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device having one or more processors, etc.). For example, machine-readable storage media include recordable / non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, etc.).

[0253] The foregoing description of embodiments of the invention (including the description in the abstract) is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments and examples of the invention have been described herein for illustrative purposes, those skilled in the art will recognize that various modifications can be made within the scope of the invention.

[0254] These modifications to the invention are possible in light of the above detailed description. The terminology used in the following claims should not be construed as limiting the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention is fully defined by the following claims, which should be interpreted in accordance with established principles of claim interpretation.

Claims

1. A light detection and ranging (LIDAR) sensor, comprising: A light source configured to emit a light beam, wherein at least a portion of the light beam forms a first local oscillator signal and a second local oscillator signal; Multiple LiDAR pixels; and A local oscillator module, coupled to the plurality of LiDAR pixels, is configured to receive a first local oscillator (LOS) signal and a second local oscillator (LOP) signal. The local oscillator module includes multiple LOS output ports and multiple LOP output ports. The LOS output port and the LOP output port are arranged alternately. The adjacent pairs of LOS output ports and LOP output ports among the plurality of LOS output ports are configured to simultaneously output the LOS signal and different LOP signals from the local oscillator module to a specific LIDAR pixel.

2. The LIDAR sensor as described in claim 1, wherein, The local oscillator module is configured to selectively provide the first local oscillator signal and the second local oscillator signal to the beam-transmitting LIDAR pixels among the plurality of LIDAR pixels.

3. The LIDAR sensor as described in claim 1, wherein, The local oscillator module is configured as follows: The first local oscillator signal is provided to the multiple LOS output ports to the multiple LIDAR pixels, and The second local oscillator signal is provided to the multiple LIDAR pixels through the multiple LOP output ports.

4. The LIDAR sensor as described in claim 1, wherein the plurality of LIDAR pixels respectively comprise: (i) A first optical antenna configured to transmit a beam to the surrounding environment; as well as (ii) A second optical antenna configured to detect a returning beam that indicates the transmitted beam is reflected back from an object in the surrounding environment.

5. The LIDAR sensor as claimed in claim 4, further comprising: A beam splitter is configured to split the beam into a transmitted signal and a local oscillator signal; A transmit beam module is configured to receive the transmit signal and is coupled to the plurality of LIDAR pixels; as well as A polarization module is configured to receive the local oscillator signal and generate the first local oscillator signal and the second local oscillator signal.

6. The LIDAR sensor as described in claim 5, wherein, The first local oscillator signal and the second local oscillator signal have the same polarization orientation.

7. The LIDAR sensor as claimed in claim 5, wherein, The first local oscillator signal and the second local oscillator signal have different polarization orientations.

8. The LIDAR sensor of claim 5, further comprising: One or more processors are configured to simultaneously drive the transmit signal, the first local oscillator signal, and the second local oscillator signal one at a time to specific LIDAR pixels among the plurality of LIDAR pixels, in order to scan the plurality of LIDAR pixels sequentially.

9. The LIDAR sensor of claim 8, further comprising: A power monitor, which is coupled to the specific LiDAR pixel, The power monitor is configured to detect the amount of power in the transmitted signal provided to the specific LIDAR pixel.

10. The LIDAR sensor as claimed in claim 8, wherein, The one or more processors are configured to: drive the transmit beam module to provide the transmit signal to the specific LIDAR pixel, and simultaneously drive the local oscillator module to provide the first local oscillator signal and the second local oscillator signal to the specific LIDAR pixel.

11. The LIDAR sensor as claimed in claim 8, wherein, The specific LIDAR pixels include: A first receiver is configured to receive (i) a first polarization orientation of the returned beam; and (ii) a first local oscillator signal from the local oscillator module; and A second receiver is configured to receive (i) the second polarization orientation of the returned beam; and (ii) the second local oscillator signal from the local oscillator module.

12. The LIDAR sensor as claimed in claim 11, wherein, The second optical antenna includes a dual polarization receiving grating, configured as follows: (i) directing the first polarization orientation of the returning beam toward the first receiver; and (ii) Guide the second polarization orientation of the returned beam to the second receiver.

13. The LIDAR sensor as claimed in claim 11, wherein, The second optical antenna includes: A first polarization receiving grating is configured to direct a first polarization orientation of the returned beam toward the first receiver; and A second polarization receiving grating is configured to direct the second polarization orientation of the returned beam to the second receiver. The first polarization receiving grating and the second polarization receiving grating are spaced apart.

14. The LIDAR sensor as claimed in claim 11, wherein, The first receiver includes a first optical mixer, and wherein, The second receiver includes a second optical mixer.

15. The LIDAR sensor as claimed in claim 1, wherein, The local oscillator module includes multiple optical switches arranged in a multi-layer configuration.

16. The LIDAR sensor as claimed in claim 15, wherein, The multi-layer configuration includes: The first group of the plurality of optical switches; A second group of the plurality of optical switches, the second group comprising more optical switches than the first group; and The third group of the plurality of optical switches contains more optical switches than the second group.

17. The LIDAR sensor as claimed in claim 16, wherein: The first group includes an optical switch; The second group includes two optical switches; and The third group includes four optical switches.

18. An autonomous vehicle control system for an autonomous vehicle, the autonomous vehicle control system comprising: Light detection and ranging (LIDAR) sensors, including: A light source configured to emit a light beam, wherein at least a portion of the light beam forms a first local oscillator signal and a second local oscillator signal; Multiple LiDAR pixels; and A local oscillator module, coupled to the plurality of LiDAR pixels, is configured to receive a first local oscillator (LOS) signal and a second local oscillator (LOP) signal. The local oscillator module includes multiple LOS output ports and multiple LOP output ports. in, The LOS output port and the LOP output port are arranged alternately. The adjacent pairs of LOS output ports and LOP output ports among the plurality of LOS output ports are configured such that the local oscillator module simultaneously outputs the LOS signal and different LOP signals to a specific LIDAR pixel.

19. The autonomous vehicle control system as described in claim 18, wherein, The local oscillator module is configured to selectively transmit LIDAR pixels to the beam of the plurality of LIDAR pixels, and provide the first local oscillator signal and the second local oscillator signal.

20. An autonomous vehicle, comprising: Light detection and ranging (LIDAR) sensors, including: A light source configured to emit a light beam, wherein at least a portion of the light beam forms a first local oscillator signal and a second local oscillator signal; Multiple LiDAR pixels; and A local oscillator module, coupled to the plurality of LiDAR pixels, is configured to receive a first local oscillator (LOS) signal and a second local oscillator (LOP) signal. The local oscillator module includes multiple LOS output ports and multiple LOP output ports. The LOS output port and the LOP output port are arranged alternately. The adjacent pairs of LOS output ports and LOP output ports among the plurality of LOS output ports are configured such that the local oscillator module simultaneously outputs the LOS signal and different LOP signals to a specific LIDAR pixel.

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