LIDAR with switchable local oscillator signal

Abstract

A light detection and ranging (LIDAR) sensor system includes a plurality of LIDAR pixels and a local oscillator module. A 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 a first local oscillator signal or a second local oscillator signal to a first LIDAR pixel of the plurality of LIDAR pixels.

Description

[0001] Related Applications

[0002] This application is based upon and claims the benefit of U.S. Non-Provisional Patent Application No. 18 / 161,441, filed January 30, 2023, and a continuation of U.S. Non-Provisional Patent Application No. 18 / 160,817, filed January 27, 2023, and a continuation of U.S. Non-Provisional Patent Application No. 17 / 750,247, filed May 20, 2022. This application is also based upon and 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 entireties. Background Art

[0003] Frequency modulated continuous wave (FMCW) light detection and ranging (LIDAR) directly measures the range and speed of an object by emitting a frequency modulated light beam and detecting the return signal. The automotive industry is currently developing autonomous features for controlling vehicles in specific situations. According to SAE International Standard J3016, there are 6 levels of autonomy, ranging from Level 0 (no autonomy) to Level 5 (the vehicle is able to operate without operator input under arbitrary conditions). Vehicles with autonomous features utilize sensors to perceive the environment through which the vehicle is driving. Acquiring and processing data from the sensors allows the vehicle to navigate its environment. Summary of the invention

[0004] Embodiments of the present disclosure include a light detection and ranging (LIDAR) sensor system including 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 a first LIDAR pixel in the plurality of LIDAR pixels.

[0005] In an embodiment, a 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 the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0006] In an embodiment, the one or more processors are further configured to: drive the local oscillator module to provide the first local oscillator signal and the second local oscillator signal to a second LIDAR pixel among the plurality of LIDAR pixels; and drive the 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.

[0007] In an embodiment, the transmit beam module is configured to provide a transmit beam to a specific LIDAR pixel among the plurality of LIDAR pixels.

[0008] In an embodiment, the one or more processors are configured to drive the transmit beam module to provide a transmit beam to the first LIDAR pixel, while the one or more processors drive the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0009] In an embodiment, at least a first LIDAR pixel and a second LIDAR pixel of a plurality of LIDAR pixels include: (1) a transmit optical antenna for transmitting a transmit beam; (2) a receive optical antenna for detecting a return beam; (3) 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 (4) a second receiver configured to receive (i) a second polarization orientation of the return beam; and (ii) a second local oscillator signal from the local oscillator module.

[0010] In an embodiment, the receiving optical antenna includes: a first polarization receiving grating configured to direct a first polarization orientation of a return beam to a first receiver; and a second polarization receiving grating configured to direct a second polarization orientation of the return beam to a second receiver. The first polarization receiving grating is spaced apart from the second polarization receiving grating.

[0011] In an embodiment, the first receiver includes a first optical mixer and the second receiver includes a second optical mixer.

[0012] In an embodiment, the local oscillator module is configured to provide the first local oscillator signal and the second local oscillator signal to only one particular LIDAR pixel of the plurality of LIDAR pixels at any given time.

[0013] In an embodiment, the LIDAR sensor system further comprises a light source configured to emit near infrared light; and a beam splitter configured to split the near infrared light into a transmission signal and a local oscillator signal. At least one of the first local oscillator signal and the second local oscillator signal is derived from the local oscillator signal.

[0014] In an embodiment, the local oscillator module comprises at least two optical switches.

[0015] In an embodiment, 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.

[0016] In an embodiment, the first polarization orientation is orthogonal to the second polarization orientation.

[0017] Embodiments of the present 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 signal. The LIDAR device includes a plurality of LIDAR pixels configured to generate a beat 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 a first local oscillator signal and a second local oscillator signal to a first LIDAR pixel in the plurality of LIDAR pixels.

[0018] In an embodiment, the autonomous vehicle control system further includes a transmit beam module configured to receive a transmit beam. The one or more processors are configured to drive (i) the transmit beam module to provide a transmit beam to the first LIDAR pixel, and (ii) the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0019] In an embodiment, the one or more processors are further configured to: drive the local oscillator module to provide the first local oscillator signal and the second local oscillator signal to the second first LIDAR pixel among the plurality of LIDAR pixels; and drive the transmit beam module to provide the 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.

[0020] In an embodiment, the transmit beam module is configured to provide a transmit beam to a specific LIDAR pixel among the plurality of LIDAR pixels.

[0021] In an embodiment, the one or more processors are configured to drive the transmit beam module to provide a transmit beam to the first LIDAR pixel, while the one or more processors drive the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0022] Embodiments of the present disclosure include an autonomous vehicle including a light detection and ranging (LIDAR) device and one or more processors configured to control the autonomous vehicle in response to a beat signal. The LIDAR device includes a plurality of LIDAR pixels configured to generate a beat 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 a first LIDAR pixel of the plurality of LIDAR pixels.

[0023] Embodiments of the present 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 the 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 a specific LIDAR pixel 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 configured to detect an amount of power in a transmit beam provided to the first LIDAR pixel.

[0024] In an embodiment, the one or more processors are configured to drive the transmit beam module to provide a transmit beam to the first LIDAR pixel, while the one or more processors drive the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0025] In an embodiment, a 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 the local oscillator module.

[0026] In an embodiment, the second optical antenna includes a dual polarization receive grating configured to: (i) direct a first polarization orientation of the return beam to the first receiver, and (ii) direct a second polarization orientation of the return beam to the second receiver.

[0027] In an embodiment, the second optical antenna includes a first polarization receiving grating configured to direct the first polarization orientation of the return beam to the first receiver. The second optical antenna includes a second polarization receiving grating configured to direct the second polarization orientation of the return beam to the second receiver. The first polarization receiving grating is spaced apart from the second polarization receiving grating.

[0028] In an embodiment, the first receiver includes a first optical mixer. The second receiver includes a second optical mixer.

[0029] In an embodiment, the local oscillator module is configured to provide the first local oscillator signal and the second local oscillator signal to only one particular LIDAR pixel of the plurality of LIDAR pixels at any given time.

[0030] In an embodiment, the local oscillator module includes a plurality of optical switches arranged in a multi-layer configuration.

[0031] In an embodiment, 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.

[0032] In an embodiment, the first polarization orientation is orthogonal to the second polarization orientation.

[0033] Embodiments of the present disclosure include an autonomous vehicle control system for an autonomous vehicle. 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 a specific LIDAR pixel 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 configured to detect an amount of power in the transmit beam provided to the first LIDAR pixel.

[0034] In an embodiment, the one or more processors are configured to drive the transmit beam module to provide a transmit beam to the first LIDAR pixel, while the one or more processors drive the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0035] Embodiments of the present disclosure include an autonomous vehicle. 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 the 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 a specific LIDAR pixel 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 configured to detect an amount of power in a transmit beam provided to the first LIDAR pixel.

[0036] In an embodiment, the power monitor includes a detector.

[0037] In an embodiment, the detector comprises a photodiode.

[0038] In an embodiment, at least one of the local oscillator module or the transmit beam module includes a plurality of optical switches in a multi-layer configuration.

[0039] In an embodiment, the local oscillator module includes a first plurality of optical switches arranged in a first multi-layer configuration; and 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.

[0040] In an embodiment, the first multi-layer configuration includes more switches than the second multi-layer configuration.

[0041] In an embodiment, a LIDAR sensor system includes a first waveguide coupled between a polarization module and a first local oscillator input of a local oscillator module; and a second waveguide coupled between the polarization module and a second local oscillator input of the local oscillator module.

[0042] In an embodiment, the power monitor further comprises: a first waveguide through which the transmit beam passes; and a second waveguide configured to receive a portion of the transmit beam from the first waveguide. A detector configured to convert a portion of the transmit beam into an electrical signal to support power monitoring.

[0043] Embodiments of the present 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 transmit 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 transmit 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.

[0044] In an embodiment, the multilayer configuration includes a first layer, the first layer including a first plurality of optical switches. The multilayer configuration includes a second layer, the second layer including a second plurality of optical switches, the second plurality including more optical switches than the first plurality. The multilayer configuration includes a third layer, the third layer including a third plurality of optical switches, the third plurality including more optical switches than the second plurality.

[0045] In an embodiment, the first group includes one optical switch, the second group includes two optical switches, and the third group includes four optical switches.

[0046] In an embodiment, the switching device further comprises an optical device coupling the optical switches in the second group with the two optical switches in the third group.

[0047] In an embodiment, an optical device includes a waveguide junction.

[0048] In an embodiment, the plurality of optical switches are independently controlled.

[0049] In an embodiment, a plurality of optical switches are operable to direct transmit beams one at a time to a plurality of transmitters.

[0050] In an embodiment, a transmit beam transmitted by a first transmitter of the plurality of transmitters is reflected from an object as a return beam, which is received by the first transmitter.

[0051] In an embodiment, the first transmitter includes a transmit circuit configured to transmit a transmit beam and a receiver circuit configured to receive a return beam.

[0052] In an embodiment, the light source comprises a laser.

[0053] In an embodiment, the LIDAR sensor includes a local oscillator configured to receive a local oscillator signal. The local oscillator includes a plurality of optical switches arranged in a multi-layer configuration and operable to sequentially transmit the local oscillator signal to a plurality of transmitters.

[0054] In an embodiment, the LIDAR sensor includes a polarization module coupled between the local oscillator and the beam splitter. The polarization module is configured to receive the 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.

[0055] In an embodiment, the second polarization orientation is orthogonal to the first polarization orientation.

[0056] In an embodiment, a LIDAR sensor includes a first interface optically coupling a switching device to a plurality of emitters and a second interface optically coupling a local oscillator to the plurality of emitters.

[0057] In an embodiment, at least a first transmitter of the plurality of transmitters comprises a first optical antenna configured to transmit a light beam into a surrounding environment and a second optical antenna configured to detect a return beam.

[0058] In an embodiment, the second optical antenna comprises a dual polarization optical antenna configured to detect a first polarization orientation of the return beam and a second polarization orientation of the return beam.

[0059] In an embodiment, at least a first transmitter among the multiple transmitters also 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 a return 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 return beam.

[0060] In an embodiment, the LIDAR sensor includes a plurality of power monitors configured to monitor an amount of power in a transmit beam emitted by a corresponding transmitter of the plurality of transmitters.

[0061] Embodiments of the present 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 transmit 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 transmit beam, the switching device including a plurality of optical switches arranged in a multi-layer configuration and operable to sequentially transmit the transmit beam to the plurality of transmitters.

[0062] Embodiments of the present disclosure include an autonomous vehicle. 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 transmit 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 transmit beam. The switching device includes a plurality of optical switches arranged in a multi-layer configuration and operable to sequentially transmit the transmit beam to the plurality of transmitters.

[0063] Embodiments of the present disclosure include a light detection and ranging (LIDAR) sensor. The LIDAR sensor includes a light source configured to send a light beam. The LIDAR sensor includes a plurality of LIDAR pixels, each including: (i) a first optical antenna configured to send a light beam into a surrounding environment; and (ii) a second optical antenna configured to detect a return beam indicating that the light beam is reflected from an object in the surrounding environment. The LIDAR sensor includes a switching device, the switching device including a plurality of optical switches arranged in a multi-layer configuration, the plurality of optical switches being operable to sequentially transmit the light beam to corresponding LIDAR pixels in the plurality of LIDAR pixels to transmit the light beam into the surrounding environment. The LIDAR sensor includes a local oscillator module, the local oscillator module being configured to receive one or more local oscillator signals and transmit the one or more local oscillator signals to corresponding LIDAR pixels.

[0064] In an embodiment, a multi-layer configuration includes: a first layer, which includes a first plurality of optical switches; a second layer, which includes a second plurality of optical switches, the second group includes more optical switches than the first group; and a third layer, which includes a third plurality of optical switches, the third group includes more optical switches than the second group.

[0065] In an embodiment, the first group includes one optical switch, the second group includes two optical switches, and the third group includes four optical switches.

[0066] In an embodiment, the switching device further comprises an optical device coupling the optical switches in the second group with the two optical switches in the third group.

[0067] In an embodiment, an optical device includes a waveguide junction.

[0068] In an embodiment, the plurality of optical switches are independently controlled.

[0069] In an embodiment, a plurality of optical switches are operable to deliver light beams to a plurality of LIDAR pixels one at a time.

[0070] In an embodiment, the 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.

[0071] In an implementation, a 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.

[0072] In an embodiment, the second polarization is orthogonal to the first polarization.

[0073] In an embodiment, the second optical antenna comprises a dual polarization optical antenna configured to detect a first polarization orientation of the return beam and a second polarization orientation of the return beam.

[0074] In an embodiment, the light source comprises a laser and the light beam comprises a laser beam.

[0075] In an embodiment, the LIDAR sensor includes a power monitor configured to monitor the amount of power contained in the light beam sent to the corresponding LIDAR pixel.

[0076] In an embodiment, the LIDAR sensor includes one or more processors configured to: (i) drive a switching device to transmit a light beam 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 the corresponding LIDAR pixels.

[0077] In an embodiment, one or more processors are configured to drive the local oscillator module to transmit one or more local oscillator signals to the corresponding LIDAR pixels, while one or more processors are configured to drive the switching device to transmit the light beam to the corresponding LIDAR pixel.

[0078] In an embodiment, a plurality of LIDAR pixels and a local oscillator module are disposed on a substrate.

[0079] In an embodiment, the plurality of LIDAR pixels further include a receiver respectively configured to convert the return beam received by the second optical antenna into an electrical signal.

[0080] In an embodiment, the receiver includes one or more photodiodes.

[0081] Embodiments of the present 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 send a light beam into a surrounding environment; and (ii) a second optical antenna configured to detect a return beam indicating that the light beam is reflected from an object in the surrounding environment. The LIDAR system includes a switching device, the switching device including 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 into the surrounding environment. The LIDAR system includes a local oscillator module, the local oscillator module being configured to receive one or more local oscillator signals and transmit the one or more local oscillator signals to the corresponding LIDAR pixels.

[0082] Embodiments of the present disclosure include an autonomous vehicle. 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 send a light beam into a surrounding environment; and (ii) a second optical antenna configured to detect a return beam indicating that the light beam is reflected from an object in the surrounding environment. The LIDAR system includes a switching device, the switching device including 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 into the surrounding environment. The LIDAR system includes a local oscillator module, the local oscillator module being configured to receive one or more local oscillator signals and transmit the one or more local oscillator signals to the corresponding LIDAR pixels.

[0083] Embodiments of the present 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 in the LIDAR device. 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 transmit beam. The receiving optical antenna is configured to detect (i) a first polarization orientation of a return beam and (ii) a second polarization orientation of the return beam. At least one receiver is configured to generate at least one signal based on (i) the return beam and (ii) at least one of the multiple local oscillator signals. The at least one signal represents a distance to an object.

[0084] In an 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.

[0085] In an embodiment, the first local oscillator signal has a first polarization orientation and the second local oscillator signal has a second polarization orientation.

[0086] In an embodiment, the at least one signal includes a first signal and a second signal. The first receiver is configured to generate the first signal representing a return beam of a first polarization orientation, and the second receiver is configured to generate the second signal representing a return beam of a second polarization orientation.

[0087] In an 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.

[0088] In an 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 directionally couple a first polarization of the return beam to at least one receiver. The second single polarization grating coupler is configured to directionally couple a second polarization of the return beam to at least one receiver.

[0089] In an embodiment, the transmit optical antenna includes a third single polarization grating coupler configured to emit a transmit beam having a first polarization orientation. The first single polarization grating coupler is offset from the second single polarization grating coupler, and the second single polarization grating coupler is offset from the third single polarization grating coupler.

[0090] In an embodiment, the first single polarization grating coupler is orthogonal to or can be rotated about 90 degrees relative to the second single polarization grating coupler.

[0091] In an embodiment, the local oscillator network includes an optical splitter configured to (i) receive a first local oscillator signal and (ii) provide a plurality of local oscillator signals to respective pixels of the plurality of LIDAR pixels.

[0092] In an embodiment, the local oscillator network is configured to provide at least two of the plurality of local oscillator signals to each of the plurality of LIDAR pixels.

[0093] In an embodiment, the LIDAR device further comprises at least one passive optical splitter configured to couple the transmit signal to at least two of the one or more LIDAR pixels.

[0094] In an embodiment, the LIDAR device further comprises a plurality of power monitors. One of the plurality of power monitors is coupled to the transmit optical antenna. One of the plurality of power monitors comprises at least one photodiode configured to generate an electrical output signal representing the power amount of the transmit signal.

[0095] In an embodiment, at least one of the plurality of LIDAR pixels further comprises an optical rotator configured to couple the transmit signal to the transmit optical antenna and configured to couple the return beam to the at least one receiver.

[0096] In an 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.

[0097] In an embodiment, the first semiconductor layer includes a Group III or Group V element, and the second semiconductor layer is a nitride layer.

[0098] In an embodiment, the first polarization orientation is orthogonal to the second polarization orientation.

[0099] Embodiments of the present 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 multiple local oscillator signals in the LIDAR device. 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 transmit beam. The receiving optical antenna is configured to detect (i) a first polarization orientation of a return beam and (ii) a second polarization orientation of the return beam. At least one receiver is configured to generate at least one signal based on (i) the return beam and (ii) at least one of the multiple local oscillator signals. The at least one signal represents a distance to an object.

[0100] In an 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 directionally couple a first polarization of a return beam to at least one receiver, and the second single polarization grating coupler is configured to directionally couple a second polarization of the return beam to at least one receiver.

[0101] In an 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.

[0102] Embodiments of the present disclosure include an autonomous vehicle. 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 in the LIDAR device. One or more LIDAR pixels are coupled to the local oscillator network. At least one of the one or more LIDAR pixels includes a transmit optical antenna, a receive optical antenna, and at least one receiver. The transmit optical antenna is configured to transmit a transmit beam. The receive optical antenna is configured to detect (i) a first polarization orientation of a return beam and (ii) a second polarization orientation of the return beam. At least one receiver is configured to generate at least one signal based on (i) the return beam and (ii) at least one of the multiple local oscillator signals. The at least one signal represents a distance to an object.

[0103] Embodiments of the present 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 LIDAR pixel 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 of 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 an amount of power in the transmit beam provided to the first LIDAR pixel.

[0104] In an embodiment, the one or more processors are configured to drive the transmit beam module to provide a transmit beam to the first LIDAR pixel, while the one or more processors drive the local oscillator module to provide a first local oscillator signal and a second local oscillator signal to the first LIDAR pixel.

[0105] In an embodiment, a 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 the local oscillator module.

[0106] In an embodiment, the second optical antenna includes a dual polarization receive grating configured to: (i) direct a first polarization orientation of the return beam to the first receiver, and (ii) direct a second polarization orientation of the return beam to the second receiver.

[0107] In an embodiment, the second optical antenna includes: a first polarization receiving grating configured to direct a first polarization orientation of a return beam to the first receiver; and a second polarization receiving grating configured to direct a second polarization orientation of the return beam to the second receiver. The first polarization receiving grating is spaced apart from the second polarization receiving grating.

[0108] In an embodiment, the first receiver comprises a first optical mixer, and wherein the second receiver comprises a second optical mixer.

[0109] In an embodiment, the local oscillator module is configured to provide the first local oscillator signal and the second local oscillator signal to only one particular LIDAR pixel of the plurality of LIDAR pixels at any given time.

[0110] In an embodiment, 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.

[0111] In an embodiment, the first polarization orientation is orthogonal to the second polarization orientation.

[0112] In an embodiment, at least one of the local oscillator module or the transmit beam module includes a plurality of optical switches in a multi-layer configuration.

[0113] In an 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.

[0114] In an embodiment, the first multi-layer configuration includes more switches than the second multi-layer configuration.

[0115] In an embodiment, the power monitor includes a detector. The power monitor also includes a first waveguide through which the transmit beam passes and a second waveguide configured to receive a portion of the transmit beam from the first waveguide. The detector is configured to convert the portion of the transmit beam into an electrical signal to support power monitoring.

[0116] Embodiments of the present disclosure include an autonomous vehicle control system for an autonomous vehicle. The autonomous vehicle control system includes a light detection and ranging (LIDAR) system of any of the above.

[0117] Embodiments of the present disclosure include an autonomous vehicle comprising the light detection and ranging (LIDAR) system of any of the above. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0119] Figure 1A A block diagram illustrating an example of a system environment for an autonomous vehicle according to an embodiment of the present disclosure.

[0120] FIG. 1B illustrates a block diagram of an example of a system environment for an autonomous commercial truck vehicle according to an embodiment of the present disclosure.

[0121] FIG. 1C illustrates a block diagram of an example of a system environment for an autonomous commercial truck vehicle, according to an embodiment of the present disclosure.

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

[0123] Figure 2 A LIDAR system including a local oscillator module according to an embodiment of the present disclosure is shown.

[0124] Figure 3 It is shown that the embodiment according to the present disclosure may include Figure 2 An example diagram of a LIDAR transceiver with some components of a LIDAR system.

[0125] Figure 4 An example local oscillator module according to an embodiment of the present disclosure is shown.

[0126] Figure 5 An example transmit beam module according to an embodiment of the present disclosure is shown.

[0127] 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.

[0128] Figure 7 An example coherent receiver according to an embodiment of the present disclosure is shown.

[0129] Figure 8 A process of operating a LIDAR device according to an embodiment of the present disclosure is shown.

[0130] Fig. 9 A block diagram of a LIDAR system including a LIDAR transceiver according to an embodiment of the present disclosure is shown.

[0131] Fig. 10A A schematic diagram of a LIDAR transceiver with a local oscillator network and a LIDAR pixel array is shown in accordance with an embodiment of the present disclosure.

[0132] Fig. 10B A schematic diagram of a LIDAR transceiver with a local oscillator network and a LIDAR pixel array is shown in accordance with an embodiment of the present disclosure.

[0133] Fig.11 A LIDAR pixel with a dual polarization optical antenna is shown according to an embodiment of the present disclosure.

[0134] Fig. 12A and 12B A block diagram illustrating a stacked configuration of optical antennas of a LIDAR device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0135] Embodiments of light detection and ranging (LIDAR) with switchable local oscillator signals are described herein. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. However, a person skilled in the relevant art will recognize that the techniques described herein can be implemented without one or more of the specific details, or with other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.

[0136] References in this specification to "one embodiment" or "an embodiment" mean that the particular features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places in this specification do not necessarily all refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0137] In this specification, a number of specialized terms are used. These terms should be taken to have the ordinary meaning in the art to which they belong, unless otherwise explicitly defined herein or the context of their use clearly implies other meanings. For the purpose of this specification, the term "autonomous vehicle" includes vehicles with autonomous features of any autonomy level of SAE International Standard J3016.

[0138] In various aspects of the present disclosure, visible light can be defined as having a wavelength range of about 380 nm-700 nm. Non-visible light can be defined as light having a wavelength outside the visible light range, such as ultraviolet light and infrared light. Infrared light having a wavelength range of about 700 nm-1 mm includes near infrared light. In various aspects of the present disclosure, near infrared light can be defined as having a wavelength range of about 700 nm-1600 nm.

[0139] Frequency modulated continuous wave (FMCW) LIDAR directly measures the range and velocity of an object / target by sending a frequency modulated beam of light to the object or target. The light reflected from the object / target can be combined with a tapped version of the beam. Once corrected for the Doppler shift that requires a second measurement, the frequency of the resulting beat signal is proportional to the distance of the object from the LIDAR system. The two measurements, which may or may not be taken simultaneously, provide both range and velocity information.

[0140] Embodiments of the present disclosure include LIDAR systems and devices using switchable local oscillator signals. The LIDAR device may include multiple LIDAR pixels. The 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 as a reflection of the transmit beam from a target in the environment. The 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 having a first polarization orientation, and a second optical receiver of the LIDAR pixel may receive a second local oscillator signal having a second polarization orientation different from the first polarization orientation. The first optical receiver may receive a first polarization orientation of the return signal, and the second optical receiver may receive a second polarization orientation of the return signal. Previously, a first local oscillator signal and a second local oscillator signal may 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.

[0141] In an embodiment of the present disclosure, the 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 local oscillator signal and the second local oscillator signal to a beam-transmitting LIDAR pixel among a plurality of LIDAR pixels. While providing the first local oscillator signal and the second local oscillator signal to the beam-transmitting LIDAR pixel, a transmit beam (e.g., an infrared laser) may be provided to the beam-transmitting LIDAR pixel. The transmit beam module may be configured to provide the transmit beam to any pixel of the plurality of LIDAR pixels that is a beam-transmitting LIDAR pixel. In this way, the transmit beam and the first local oscillator signal and the second local oscillator signal may be selectively (in some embodiments simultaneously) provided to one LIDAR pixel in order to scan a plurality of LIDAR pixels. The beam-transmitting 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.

[0142] Each LIDAR pixel in the plurality of LIDAR pixels may include a transmitting optical antenna, a receiving optical antenna, a first receiver, and a second receiver. The transmitting optical antenna is configured to transmit a transmit beam. The receiving 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 the local oscillator module. The first local oscillator signal may have a polarization orientation orthogonal to the second local oscillator signal. The first receiver and the second receiver may generate a first beat signal and a second beat signal. These beat signals may be used to generate a LIDAR image of the environment. These and other embodiments are described in more detail in conjunction with FIGS. 1-12B.

[0143] 1. Autonomous vehicle system environment

[0144] Figure 1A is a block diagram illustrating an example of a system environment for an autonomous vehicle, according to some implementations.

[0145] See also Figure 1A, an example autonomous vehicle 110A in which various techniques disclosed herein may be implemented. For example, the vehicle 110A may include: a powertrain 192, which includes a prime mover 194 driven by an energy source 196 and capable of providing power to a drivetrain 198; and a control system 180, which includes a directional control 182, a powertrain control 184, and a brake control 186. The vehicle 110A may be implemented as any number of different types of vehicles, including vehicles capable of transporting people and / or cargo and capable of traveling in a variety of environments, and it should be understood that the above-described components 180-198 can vary widely based on the type of vehicle in which they are used.

[0146] 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, a fuel system (e.g., providing gasoline, diesel, hydrogen, etc.), a battery system, a solar panel or other renewable energy source, and / or a fuel cell monomer system. The transmission system 198 can include wheels and / or tires and a transmission and / or any other mechanical drive assembly to convert the output of the prime mover 194 into vehicle motion, as well as one or more brakes configured to controllably stop or slow the vehicle 110A, and a direction or steering assembly suitable for controlling the trajectory of the vehicle 110A (e.g., a rack and pinion steering linkage that enables one or more wheels of the vehicle 110A to pivot about a substantially vertical axis to change the angle of the plane of rotation of the wheel relative to the longitudinal axis of the vehicle). In some embodiments, a combination of a 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 each wheel or axle) may be used as prime movers.

[0147] The direction controller 182 may include one or more actuators and / or sensors for controlling and receiving feedback from the direction or steering 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, to control the output power of the prime mover 194, to control the gear of the transmission in the transmission 198, etc., to control the speed and / or direction of the vehicle 110A. The brake control 186 may be configured to control one or more brakes that slow or stop the vehicle 110A, for example, disc brakes or drum brakes coupled to the wheels of the vehicle.

[0148] Other vehicle types (including but not limited to off-road vehicles, all-terrain or tracked vehicles, construction equipment, etc.) will necessarily use different powertrains, drivetrains, energy sources, directional controls, powertrain controls, and brake controls. In addition, in some embodiments, some components may be combined, for example, directional control of the vehicle is primarily handled by changing the output of one or more prime movers. Therefore, the embodiments disclosed herein are not limited to the specific application of the technology described herein in autonomous wheeled land vehicles.

[0149] Various levels of autonomous control of the vehicle 110A can be implemented in a vehicle control system 120, which can include one or more processors 122 and one or more memories 124, with each processor 122 configured to execute program code instructions 126 stored in the memory 124. The processor can include, for example, a graphics processing unit ("GPU") and / or a central processing unit ("CPU").

[0150] The sensor 130 may include various sensors suitable for collecting information from the surrounding environment of the vehicle for controlling the operation of the vehicle. For example, the sensor 130 may include a radar sensor 134, a LIDAR (light detection and ranging) sensor 136, a 3D positioning sensor 138, for example, an accelerometer, a gyroscope, a magnetometer, or any one of a satellite navigation system (such as GPS (Global Positioning System), GLONASS (Globalnaya Navigazionnaya Sputnikovaya Sistema or Global Navigation Satellite System), Beidou Navigation Satellite System (BDS), Galileo, compass, etc.). The 3D positioning sensor 138 can be used to determine the position of the vehicle on the earth using satellite signals. The sensor 130 can include a camera 140 and / or an IMU (Inertial Measurement Unit) 142. The camera 140 can be a single or stereo camera and can record static and / or video images. The IMU 142 can include multiple gyroscopes and accelerometers that can detect linear and rotational motion of the vehicle 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 the vehicle 110A. Each sensor 130 may be capable of outputting sensor data at various data rates, which may be different from the data rates of the other sensors 130 .

[0151] The output of the sensor 130 can be provided to a set 150 of control subsystems, which include a positioning subsystem 152, a planning subsystem 156, a perception subsystem 154, and a control subsystem 158. The positioning subsystem 152 can perform functions such as accurately determining the position and orientation (sometimes also referred to as "pose") of the vehicle 110A in its surroundings, and usually within a certain 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 can perform functions such as detecting, tracking, determining and / or identifying objects in the surrounding environment of the vehicle 110A. Machine learning models can be used to track objects. The planning subsystem 156 can perform functions such as planning a trajectory for the vehicle 110A within a certain time frame given a desired destination and static and moving objects in the environment. Machine learning can be used to plan vehicle trajectories. The control subsystem 158 can perform functions such as generating appropriate control signals for controlling various controls in the vehicle control system 120 to achieve the planned trajectory of the vehicle 110A. The machine learning model can be utilized to generate one or more signals to control the autonomous vehicle to implement the planned trajectory.

[0152] It should be understood that Figure 1A The assembly of components of the vehicle control system 120 shown in FIG. 1 is merely exemplary in nature. In some embodiments, individual sensors may be omitted. Additionally or alternatively, in some embodiments, a Figure 1A Multiple sensors of the type shown in can be used to achieve redundancy and / or cover 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. In addition, although subsystems 152-158 are shown as being separated 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 with program code instructions 126 residing in one or more memories 124 and executed by one or more processors 122, and these subsystems 152-158 can be implemented using the same processor and / or memory in some cases. The subsystem can be implemented at least in part using various dedicated circuit logic, various processors, various field programmable gate arrays ("FPGA"), various application-specific integrated circuits ("ASIC"), various real-time controllers, etc. As described above, multiple subsystems can utilize circuit systems, processors, sensors and / or other components. In addition, the various components in the vehicle control system 120 can be networked in various ways.

[0153] In some embodiments, the vehicle 110A may also include an auxiliary vehicle control system (not shown) that may be used as a redundant or backup control system for the vehicle 110A. The auxiliary vehicle control system may be able to fully operate the autonomous vehicle 110A in the event of an adverse event in the vehicle control system 120, while in other embodiments, the auxiliary vehicle control system may have only limited functionality, such as a controlled stop of the vehicle 110A in response to an adverse event detected in the primary vehicle control system 120. In other embodiments, the auxiliary vehicle control system may be omitted.

[0154] In general, there are countless different architectures that can be used to implement Figure 1A , the myriad of different architectures include various combinations of software, hardware, circuit logic, sensors, networks, etc. For example, each processor may be implemented as a microprocessor, and each memory may represent a random access memory ("RAM") device, which includes main memory as well as any supplementary levels of memory, such as cache memory, non-volatile or backup memory (e.g., programmable or flash memory), read-only memory, etc. In addition, each memory may be considered to include memory storage physically located elsewhere in the vehicle 110A, such as any cache memory in a processor, as well as any storage capacity used as virtual memory, such as stored on a mass storage device or another computer controller. Figure 1A One or more of the processors shown in , or an entirely separate processor, may be used to implement additional functionality in the vehicle 110A beyond autonomous control purposes, such as controlling entertainment systems, operating doors, lights, convenience features, etc.

[0155] In addition, for additional storage, the vehicle 110A may include one or more mass storage devices, such as a removable disk drive, a hard disk drive, a direct access storage device (“DASD”), an optical disk drive (e.g., a CD drive, a DVD drive, etc.), a solid-state storage drive (“SSD”), a network attached storage, a storage area network, and / or a tape drive, etc.

[0156] Additionally, the vehicle 110A may include a user interface 164 to enable the vehicle 110A to receive a plurality of inputs from and generate outputs to a user or operator, such as one or more displays, touch screens, voice and / or gesture interfaces, buttons and other tactile controls, etc. Otherwise, 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.

[0157] In addition, the vehicle 110A may include one or more network interfaces, such as a network interface 162, which is suitable for communicating with one or more networks 170 (e.g., a local area network ("LAN"), a wide area network ("WAN"), a 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 the vehicle 110A receives environmental and other data for its autonomous control. Data collected by one or more sensors 130 can be uploaded to a computing system 172 via the network 170 for additional processing. Prior to uploading, a timestamp can be added to each instance of vehicle data.

[0158] Figure 1A Each of the processors shown in the vehicle 110A, as well as the various additional controllers and subsystems disclosed herein, typically operates under the control of an operating system and executes or otherwise relies on various computer software applications, components, programs, objects, modules, data structures, etc., as described in more detail below. In addition, the various applications, components, programs, objects, modules, etc. may also be executed on one or more processors in another computer coupled to the vehicle 110A via the network 170, for example, in a distributed, cloud-based, or client-server computing environment, so that the processing required to implement the computer program functions can be distributed to multiple computers and / or services on the network.

[0159] In general, routines executed to implement the various embodiments described herein, whether as part of an operating system or a specific 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 various times in various memories and storage devices, and when read and executed by one or more processors, perform the steps necessary to perform the steps or elements embodying various aspects of the present disclosure. Furthermore, while the embodiments have been and will be described below in the context of fully functional computers and systems, it should be understood that the various embodiments described herein can be distributed as program products in various forms, and that the embodiments can be implemented regardless of the specific type of computer-readable medium used to actually perform the distribution.

[0160] Examples of computer-readable media include tangible, non-transitory media such as volatile and non-volatile memory devices, floppy disks and other removable disks, solid-state drives, hard drives, magnetic tapes, and optical disks (e.g., CD-ROMs, DVDs, etc.), among others.

[0161] In addition, various program codes described hereinafter can be identified according to the application implemented in a specific embodiment. However, it should be understood that any specific program nomenclature hereinafter is only used for convenience, so the present disclosure should not be limited to use in any specific application that is only identified and / or implied by the nomenclature. In addition, in view of the fact that computer programs can be organized into routines, processes, methods, modules, objects, etc., the ways are usually endless, and the various ways in which program functionality can be distributed among the various software layers (e.g., operating systems, libraries, APIs, applications, applets, etc.) resident in typical computers, it should be understood that the present disclosure is not limited to the specific organization and distribution of the program functionality described herein.

[0162] Figure 1A The environment shown in is not intended to limit the embodiments disclosed herein. In fact, other alternative hardware and / or software environments can be used without departing from the scope of the embodiments disclosed herein.

[0163] 2. FM LIDAR for automotive applications

[0164] The truck can include a LIDAR system (e.g. Figure 1A The vehicle control system 120, Figure 2 200, etc.). In some embodiments, the LIDAR system can encode the light signal using frequency modulation and scatter the coded light signal into free space using optics. By detecting the frequency difference between the coded light signal and the return signal reflected from the object, a frequency modulation (FM) LIDAR system can determine the position of the object and / or accurately measure the velocity of the object using the Doppler effect. FM LIDAR systems can use continuous waves (referred to as "FMCW LIDAR" or "coherent FMCW LIDAR") or quasi-continuous waves (referred to as "FMQW LIDAR"). The LIDAR system can encode the light signal using phase modulation (PM) and scatter the coded light signal into free space using optics.

[0165] FM or phase modulation (PM) LIDAR systems may have significant advantages over traditional LIDAR systems for automotive and / or commercial truck applications. First, in some cases, an object (e.g., a pedestrian wearing dark clothing) may have low reflectivity, reflecting only a small amount of the light striking the object (e.g., 10% or less) back to the FM or PM LIDAR system's sensor (e.g., Figure 1A In other cases, an object (e.g., a shiny road sign) may have a high reflectivity (e.g., greater than 10%) because it reflects a large amount of light striking the object back to the sensor of the FM LIDAR system.

[0166] Regardless of the reflectivity of the object, the FM LIDAR system is able to detect (e.g., classify, identify, find, etc.) objects at a greater distance (e.g., 2 times) than a conventional LIDAR system. For example, the FM LIDAR system can detect low reflectivity objects at a distance of 300 meters, and high reflectivity objects at a distance of 400 meters.

[0167] To achieve this improvement in detection capabilities, FM LIDAR systems can use sensors (e.g. Figure 1A Sensors 130 in. In some embodiments, these sensors can be single photon sensitive, meaning they are able to 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, it is not limited to the infrared wavelength range (e.g., near infrared: 800 nm-1500 nm; mid-infrared: 1500 nm-5600 nm; and far infrared: 5600 nm-1,000,000 nm). By operating a FM or PM LIDAR system at infrared wavelengths, the FM or PM LIDAR system is able to broadcast more intense 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, requiring them to limit their light output (and distance detection capabilities) for eye safety reasons.

[0168] 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) driving at highway speeds.

[0169] Another advantage of an FM LIDAR system is that it can provide accurate velocity for each data point instantly. In some embodiments, velocity measurement is achieved using the Doppler effect, which shifts 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 velocities encountered on road conditions with speeds less than 100 meters per second (m / s), this shift at a wavelength of 1550 nanometers (nm) equates to a frequency shift of less than 130 megahertz (MHz). This frequency shift is so small that it is difficult to detect directly in the optical domain. However, by using coherent detection in an FMCW, PMCW, or FMQW LIDAR system, the signal can be converted to the RF domain, enabling the frequency shift to be calculated using various signal processing techniques. This enables the autonomous vehicle control system to process incoming data more quickly.

[0170] Instantaneous velocity calculations also make it easier for FM LIDAR systems to identify distant or sparse data points as objects and / or to track how these objects move over time. For example, FM LIDAR sensors (e.g., Figure 1A A sensor 130 in the FM LIDAR system may receive only a few returns (e.g., hits) for an object that is 300 meters away, but if those returns give velocity values ​​of interest (e.g., moving toward the vehicle at >70 mph), the FM LIDAR system and / or the autonomous vehicle control system can determine a corresponding weight for the probability of being associated with the object.

[0171] The faster the FM LIDAR system can identify and / or track an object, the more time the autonomous vehicle control system has to maneuver the vehicle. Better knowledge of how fast an object is moving also allows the autonomous vehicle control system to plan a better response.

[0172] Another advantage of FM LIDAR systems is that they are less susceptible to static interference than traditional LIDAR systems. That is, traditional LIDAR systems, which are designed to be more sensitive to light, generally do not perform well 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 previous light pulse or beam). To overcome these shortcomings, vehicles using traditional LIDAR systems generally require additional hardware, complex software, and / or more computing power to manage this "noise."

[0173] In contrast, FM LIDAR systems do not have such issues because each sensor is specifically designed to respond only to its own light characteristics (e.g., light beam, light wave, light pulse). If the returning light does not match the time, frequency, and / or wavelength originally sent, the FM sensor is able to filter (e.g., delete, ignore, etc.) that data point. As a result, FM LIDAR systems produce (e.g., generate, derive, etc.) more accurate data and have fewer hardware or software requirements, resulting in safer and smoother driving.

[0174] Finally, FM LIDAR systems are more scalable than traditional LIDAR systems. As more self-driving vehicles (e.g., cars, commercial trucks, etc.) appear on the road, cars driven by FM LIDAR systems may not have to face interference issues caused by sensor crosstalk. In addition, FM LIDAR systems use less peak power of light than traditional LIDAR sensors. Therefore, some or all of the optical components of FM LIDAR can be produced on a single chip, which has its own benefits, as described in this article.

[0175] 3. Commercial Trucks

[0176] Figure 1B1 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, 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 plurality of modes of transportation to move cargo), and / or any other road-based freight application. 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 moving truck, etc. Cargo 106B may be goods and / or products. Commercial truck 102B may include a trailer for carrying cargo 106B, such as a flatbed trailer, a low bed trailer, a step trailer, a retractable flatbed trailer, a side trailer, etc.

[0177] Environment 100B includes object 110B (in Figure 1B The distance range between the truck and the vehicle is equal to or less than 30 meters.

[0178] The commercial truck 102B may include a LIDAR system 104B (e.g., an FM LIDAR system, Figure 1A The vehicle control system 120 in the example above is used to determine the distance to the object 110B and / or measure the speed of the object 110B. Figure 1B One LIDAR system 104B is shown mounted on the front of the commercial truck 102B, but the number of LIDAR systems and the area where the LIDAR systems are mounted 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 on any area (e.g., front, rear, side, top, bottom, under, and / or bottom) of the commercial truck 102B to facilitate detection of objects in any free space relative to the commercial truck 102B.

[0179] As shown, LIDAR system 104B in environment 100B may be configured to detect objects (eg, another vehicle, a bicycle, a tree, a street sign, a pothole, etc.) at a close distance (eg, 30 meters or less) from commercial truck 102B.

[0180] Figure 1C 1 is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some implementations. Environment 100C includes the same components included in environment 100B (eg, commercial truck 102B, cargo 106B, LIDAR system 104B, etc.).

[0181] Environment 100C includes object 110C (in Figure 1CThe LIDAR system 104B in the environment 100C may be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a road sign, a pothole, etc.) at a distance (e.g., 100 meters) from the commercial truck 102B.

[0182] Figure 1D 1 is a block diagram illustrating an example of an autonomous commercial truck vehicle system environment according to some implementations. Environment 100D includes the same components included in environment 100B (eg, commercial truck 102B, cargo 106B, LIDAR system 104B, etc.).

[0183] Environment 100D includes objects 110D (in Figure 1D As shown in the figure, the LIDAR system 104B in the environment 100D can be configured to detect objects (e.g., another vehicle, a bicycle, a tree, a road sign, a pothole, etc.) at a certain distance (e.g., 300 meters) from the commercial truck 102B.

[0184] In commercial truck applications, due to the increased weight and therefore longer stopping distances required for such vehicles, it is very important to effectively detect objects in all ranges. Due to the above advantages, FM LIDAR systems (e.g., FMCW and / or FMQW systems) or PM LIDAR systems are very suitable for commercial truck applications. Therefore, commercial trucks equipped with such systems can enhance the ability to safely transport people and goods over short or long distances, thereby improving not only the safety of commercial trucks, but also the safety of surrounding vehicles. In various embodiments, such FM or PM LIDAR systems can be used for semi-autonomous applications, where the commercial truck has a driver and some functions of the commercial truck are operated autonomously using the FM or PM LIDAR system, or fully autonomous applications, where the commercial truck is completely operated by the FM or LIDAR system alone or in combination with other vehicle systems.

[0185] 4. Continuous wave modulation and quasi-continuous wave modulation

[0186] In a LIDAR system that uses CW modulation, the modulator modulates the laser continuously. For example, if the modulation period is 10 seconds, the input signal is modulated for the entire 10 seconds. In contrast, in a LIDAR system that uses quasi-CW modulation, the modulator modulates the laser to have both an active portion and an inactive portion. For example, for a 10 second period, the modulator only modulates the laser for 8 seconds (sometimes called the "active portion"), but does not modulate the laser for 2 seconds (sometimes called the "inactive portion"). By doing this, the LIDAR system may be able to reduce power consumption for the 2 seconds because the modulator does not have to provide a continuous signal.

[0187] In frequency modulated continuous wave (FMCW) LIDAR for automotive applications, it may be beneficial to operate the LIDAR system using quasi-continuous wave modulation, where FMCW measurement and signal processing methods are used, but the optical signal is not always in the on state (e.g., enabled, powered, transmitting, etc.). In some embodiments, the duty cycle of the quasi-continuous wave modulation may be equal to or greater than 1% and may be as high as 50%. If the energy 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 in order to coherently integrate all the energy over a longer time scale.

[0188] Figure 2 FIG. 2 shows a LIDAR system 200 including a local oscillator module 212 according to an embodiment of the present disclosure. The LIDAR system 200 may be a LIDAR system 104B (eg, Figure 1B ) is an example implementation. 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 the 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 an implementation, 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 may be derived from the local oscillator signal 211 .

[0189] The local oscillator module 212 is configured to receive the first local oscillator signal 224 at a first local oscillator input 228 and the second local oscillator signal 226 at a second local oscillator input 229. The local oscillator module 212 is coupled to a plurality of LIDAR pixels in the LIDAR pixel array 214. The 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 in the plurality of LIDAR pixels.

[0190] In an embodiment, 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-transmitting LIDAR pixel. The beam-transmitting LIDAR pixel may also receive a transmit beam through the optical bus 222. The processing logic 299 may drive the local oscillator module 212 and the transmit beam module 220 to provide the transmit beam 213, the first local oscillator signal 224, and the second local oscillator signal 226 to the same LIDAR pixel (beam-transmitting LIDAR pixel) in the LIDAR pixel array 214. The processing logic 299 may drive the local oscillator module 212 and the transmit beam module 220 to sequentially provide the 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 so as to scan each LIDAR pixel as a beam-transmitting LIDAR pixel. In this way, each LIDAR pixel can transmit a transmit beam and detect a return beam as a reflection of the transmit beam from a target in the environment. Each LIDAR pixel can generate one or more beat signals by detecting the return beam, and the beat signals can be used to form a LIDAR image.

[0191] Having the system 200 provide the transmit beam 213, the first local oscillator signal 224, and the second local oscillator signal 226 to the same LIDAR pixel (rather than providing these signals to all LIDAR pixels at the same time) reduces the optical power required to operate the LIDAR system 200. Another potential advantage is a reduction in optical noise in the LIDAR system 200, which can increase the signal-to-noise ratio (SNR) of the beat frequency signal generated by the LIDAR pixels. The reduction in optical noise caused by not providing all optical signals to each LIDAR pixel at the same time may result 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 the cost of conductors (e.g., copper), reduce weight, and allow the size of the LIDAR pixel array to be reduced. In particular, for autonomous vehicles, the reduction in cost allows LIDAR systems to be deployed on more vehicles, while the reduction in weight and size allows the LIDAR pixel array to be placed in more diverse locations on the autonomous vehicle.

[0192] Figure 2An optical bus 216, an optical bus 218, and an optical bus 222 are shown. The optical bus 216 is coupled between the local oscillator module 212 and the LIDAR pixel array 214. The optical bus 218 is also coupled between the local oscillator module 212 and the LIDAR pixel array 214. The optical bus 222 is coupled between the transmit beam module 220 and the LIDAR pixel array 214. The optical bus 216 (LOS 0-7) may include eight waveguides to provide a first local oscillator signal 224 to eight LIDAR pixels of the LIDAR pixel array 214, and the optical bus 218 (LOP 0-7) may include eight waveguides to provide a second local oscillator signal 226 to eight LIDAR pixels of the LIDAR pixel array 214. Similarly, the optical bus 222 (TX 0-7) may include eight waveguides to provide a transmit beam 213 to eight LIDAR pixels of the LIDAR pixel array 214. As an example, LIDAR pixel array 214 may include any number of LIDAR pixels, such as 4, 16, 32, 48, 64, 96, or 128 LIDAR pixels. As another example, LIDAR pixel array 214 may include 3, 9, 28, or 81 LIDAR pixels. As another example, LIDAR pixel array 214 may include 5, 25, or 125 LIDAR pixels. In these examples, different numbers of LIDAR pixels can be selected to achieve a desired loss range.

[0193] Figure 2 Also shown are bus 240 and bus 242. Bus 240 (RXS 0-7) and bus 242 (RXP 0-7) may be electrical buses rather than optical buses. Bus 240 and bus 242 may carry the beat frequency signals generated by the LIDAR pixels of LIDAR pixel array 214.

[0194] Figure 3 An example diagram of a LIDAR transceiver 300 that may include component portions of the LIDAR system 200 according to an embodiment of the present disclosure is shown. According to an embodiment of the present disclosure, the LIDAR transceiver 300 includes a local oscillator module 302 that is coupled to provide a local oscillator signal to a LIDAR pixel array 304. The local oscillator module 302 may be configured the same as or similar to the local oscillator module 212.

[0195] The local oscillator (LO) module 302 may 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 an embodiment of the present disclosure, the local oscillator module 302 may be configured to provide the local oscillator signals LOS and LOP to one or more LIDAR pixels of the LIDAR pixel array 304 to enable the LIDAR pixels to generate receive signals RXS0-7 and RXP0-7 and provide the signals to the plurality of output ports 308.

[0196] The LIDAR pixel array 304 may include a plurality of LIDAR pixels positioned along one or two dimensions of the LIDAR transceiver 300 coverage area. The LIDAR pixel array 304 may be configured the same as or similar to the LIDAR pixel array 214. According to an embodiment, the LIDAR pixel 314 is an example of one or more LIDAR pixels of the LIDAR pixel array 304. According to an embodiment, the LIDAR pixel 314 may receive a transmit beam on a port 316, may receive a first local oscillator signal LOS on a port 318, and may receive a second local oscillator signal LOP on a port 320. The transmit beam module 220 ( Figure 3 (not shown) can selectively provide the transmit beam to port 316 through terminal TX7 of LIDAR transceiver 300. According to an embodiment of the present disclosure, LIDAR pixel 314 can be configured to generate a receive signal RXS and / or a receive signal RXP, and can provide one or both of the receive signals RXS and RXP to port 322 and port 324, respectively.

[0197] 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 are shown according to an embodiment of the present disclosure. The optical antenna array 326 may include at least one transmit optical antenna configured to receive a transmit beam and transmit the transmit beam into a LIDAR environment. The optical antenna array 326 may include a receive optical antenna configured to detect a return beam. The receive optical antenna may be configured to detect a first polarization orientation of the return beam and a second polarization orientation of the return 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, for example, a receive signal RXS and a receive 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 may be configured to provide a transmit signal to the optical antenna array 326 and may be configured to provide a return signal from the return optical antenna to the receiver circuitry 328 to support generation of receive signals RXS and RXP.

[0198] The LIDAR transceiver 300 may include an array of power monitors configured to detect the amount of power in each transmit signal provided to the LIDAR pixels of the LIDAR pixel array 304. The power monitor array may include one power monitor for each LIDAR pixel of the LIDAR pixel array 304. Power monitor 332 may be an example of a power monitor of the power monitor array. Power monitor 332 may include waveguide 334, waveguide 336, and photodiode 338. The transmit beam may propagate through waveguide 334, so waveguide 334 may be positioned linearly with the transmit signal waveguide. Waveguide 336 may be located near waveguide 334 to receive a portion of the transmit signal. Photodiode 338 may be coupled to waveguide 336 and may be configured to convert a portion of the transmit signal into an electrical signal to support power monitoring operations. The transceiver 300 may include a plurality of ports 340 that are communicatively coupled to the power monitors of the power monitor array and configured to provide external power monitor outputs to the transceiver 300. In some implementations, port 340 may be used to provide a control signal from processing logic (eg, processing logic 299 ) to drive local oscillator module 302 .

[0199] According to an embodiment, the transceiver 300 receives transmit beams (e.g., TX0, TX1, TX2, TX3, TX4, TX5, TX6, TX7, etc.) at a port 306 coupled to the LIDAR pixel array 304 via a plurality of 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 may be implemented in the transceiver 300 according to various embodiments of the present disclosure.

[0200] Figure 4 An example local oscillator module 499 is shown in accordance with an embodiment of the present disclosure. 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 the processing logic 299. The processing logic 299 may drive the optical switches via their respective control inputs to direct the local oscillator signal to a specific LIDAR pixel at a specific time. In an embodiment, the processing logic 299 drives the optical switches to direct the local oscillator signal to only one specific LIDAR pixel at a given time. The local oscillator module 499 may be referred to as a "2 to 2n" distribution network because it is capable of dynamically routing two signals to 2n ports, where n is a number. Figure 4 In an embodiment, n is 8 and there are 16 (2n) output ports. In one embodiment, the local oscillator module can be a "3 to 3n" distribution network because it can dynamically route three signals to 3n ports, where n is a number. In another embodiment, the local oscillator module can be a "5 to 5n" distribution network because it can dynamically route five signals to 5n ports, where n is a number. In these embodiments, a particular distribution network can be selected to achieve the desired dynamic routing and optimal signal processing.

[0201] exist Figure 4 In FIG. 4 , the optical switch 400 is configured to receive the first local oscillator signal LOS 434 and the optical switch 401 is configured to receive the second local oscillator signal LOP 436. Figure 4 In FIG. 4 , the dotted line represents a waveguide providing a first local oscillator signal 434 , and the solid line represents a waveguide providing a second local oscillator signal 436 . Figure 4 Component 441 in Figure 4In some embodiments of the local oscillator module 499, multiple waveguide stages are included so that the waveguides do not have to pass through each other, and thus the waveguide crossing component 441 is not necessary.

[0202] In an embodiment, driving a digital high (e.g., 3.3 VDC) onto the control input causes the optical switch to direct input light out of the left output port, while driving a digital low (e.g., 0 VDC) onto the control input causes the optical switch to direct input light out of the right output port. For example, to provide a first local oscillator signal 434 and a second local oscillator signal 436 to a first LIDAR pixel, control inputs X0, X1, X2, X3, X6, and X7 are driven to digital highs such that the first local oscillator signal 434 is directed to port LOS 480S, while 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, the input ports X0, X1, X2, and X3 may be driven to digital highs, and the input ports X6 and X7 may be driven to digital lows, 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 the control inputs X0, X1, X2, X3, X6, and X7 are analog signals. The processing logic 299 may continue to drive the control inputs of the optical switch to raster scan through the plurality of LIDAR pixels to provide the first local oscillator signal 434 and the second local oscillator signal 436 to facilitate generating a beat frequency signal for the beam-transmitting LIDAR pixel. The third, fourth, fifth, sixth, seventh, and eighth LIDAR pixels may receive the first local oscillator signal 434 and the second local oscillator signal 436 by driving the control ports of the optical switch. For example, the third LIDAR pixel may 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 may 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 may 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 may 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 may 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 may receive the first local oscillator signal 434 and the second local oscillator signal 436 through ports LOS 487S and LOP 487P. 487P is used to receive the first local oscillator signal 434 and the second local oscillator signal 436.

[0203] Figure 5An example transmit beam module 599 is shown in accordance with an embodiment of the present disclosure. 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 the processing logic 299. The processing logic 299 may drive the optical switches through their respective control inputs to direct the transmit beam to a specific LIDAR pixel at a specific time. In an embodiment, the processing logic 299 drives the optical switches to direct the transmit beam to only one specific LIDAR pixel at a given time.

[0204] exist Figure 5 , the optical switch 500 is configured to receive the transmit beam 513 . Figure 5 Component 541 in represents a waveguide crossing. In an embodiment, driving a digital high (e.g., 3.3 VDC) onto the control input causes the optical switch to direct input light out of the left output port, while driving a digital low (e.g., 0 VDC) onto the control input causes the optical switch to direct input light out of 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 to digital highs such that transmit beam 513 is directed to port TX 560. To provide a transmit beam 513 to a second LIDAR pixel, input ports X22 and X24 may be driven to digital highs, while input port X20 may be driven to digital low such that transmit beam 513 is directed to port TX 561. Processing logic 299 may continue to drive the control inputs of the optical switch to raster scan through a plurality of LIDAR pixels to provide the transmit beam 513 to facilitate generating a beat signal for the beam-transmitting LIDAR pixel. The third, fourth, fifth, sixth, seventh, and eighth LIDAR pixels may receive the transmit beam 513 by driving the control port of the optical switch to provide the transmit beam 513 to ports TX 562 , TX 563 , TX 564 , TX 565 , TX 566 , and TX 567 .

[0205] Figure 6 An example LIDAR pixel 699 including a first coherent receiver 621 and a second coherent receiver 626 according to an embodiment of the present disclosure is shown. 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 can be an infrared transmit beam. The transmit beam can be a near infrared transmit beam. The transmit beam can be a single defined polarization orientation. Figure 6, the transmit optical antenna 605 is shown as a single polarization output coupler and can transmit a transmit beam in response to receiving a transmit beam 601 through a waveguide 603. The transmit beam 601 can be generated by a laser and the transmit beam emitted by the transmit optical antenna 605 can have a very narrow line width (e.g., 1 nm or less). The transmit beam 601 can be selectively provided to the transmit optical antenna 605 by the transmit beam module 220.

[0206] exist Figure 6 In the illustration of , the receiving optical antenna 610 is a dual polarization receiving optical antenna configured to detect a first polarization orientation of a return beam and a second polarization orientation of the return beam. The return beam is a reflection of a transmit 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 return beam to the first coherent receiver 621 through a waveguide 612, and couple the second polarization orientation of the return beam to the second coherent receiver 626 through a waveguide 617. In an embodiment, the receiving optical antenna 610 includes a first polarization receiving grating configured to guide the first polarization orientation of the return beam to the first coherent receiver 621, and a second polarization receiving grating configured to guide the second polarization orientation of the return beam to the second coherent receiver 626. In an embodiment, the first polarization receiving grating is spaced apart from the second polarization receiving grating.

[0207] The first coherent receiver 621 is configured to generate a first signal 623 in response to receiving the first polarization orientation of the return beam and the first local oscillator signal 631. The first local oscillator signal 631 can be an optical signal having a first polarization orientation. For example, the first local oscillator signal 631 can be selectively provided by the local oscillator module 212. Figure 6 6, the first coherent receiver 621 receives the first polarization orientation of the return beam from the first single polarization grating coupler 611 through the waveguide 612, and the first coherent receiver 621 receives the first local oscillator signal 631 through the waveguide 632. The first signal 623 may be an electrical signal provided to the processing logic 650 through the communication channel 622.

[0208] The second coherent receiver 626 is configured to generate a second signal 628 in response to receiving the second polarization orientation of the return beam and the second local oscillator signal 636. The second local oscillator signal 636 can be an optical signal having a second polarization orientation. For example, the second local oscillator signal 636 can be selectively provided by the local oscillator module 212. Figure 66, a second polarization orientation of the return beam is received by the second coherent receiver 626 from the second single polarization grating coupler 616 via waveguide 617, and a second local oscillator signal 636 is received by the second coherent receiver 626 via waveguide 637. The second signal 628 may be an electrical signal provided to the processing logic 650 via the communication channel 627.

[0209] The processing logic 650 is configured to generate an image 655 in response to receiving a first signal 623 and a second signal 628 from the first coherent receiver 621 and the second coherent receiver 626, respectively. The LIDAR system 600 may include a LIDAR pixel array 699 configured to provide a first signal (e.g., signal 623) and a second signal (e.g., signal 628) to the processing logic 650. In this context, the processing logic 650 may generate the image 655 in response to the first signal and the second signal received by the processing logic 650 through a plurality of LIDAR pixels 699 in the LIDAR pixel array.

[0210] Figure 7 An example coherent receiver 771 according to an embodiment of the present disclosure is shown. In some embodiments, Figure 7 The example coherent receiver 771 of can be used as the first coherent receiver 621 and / or the second coherent receiver 626. The 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, the optical mixer 752 is configured to combine the return beam signal (RB) with the local oscillator signal (LO) to generate an output signal (OUT). For example, the optical mixer 752 can be coupled to receive the return beam signal (RB) from the waveguide 612 or the waveguide 617, and the waveguide 756 provides the return beam signal to the optical mixer 752. For example, the optical mixer 752 can be coupled to receive the local oscillator signal LO from the waveguide 632 or 637, and the waveguide 760 provides the local oscillator signal LO to the optical mixer 752. The optical mixer 752 can combine the input signals to generate a plurality of combined output signals OUT1 and OUT2. The output signals OUT1 and OUT2 are provided to a photodiode pair (including photodiodes PD1 and PD2) to convert the return beam signal RB and the local oscillator signal LO into an output signal OUT. The output signal OUT can be an electrical signal. The output signal OUT can be a beat frequency signal representing the range and / or speed of one or more objects in the environment of the LIDAR system. For example, the communication channel 622 or 627 can be coupled to the output port 762.

[0211] Figure 8A process 800 for operating a LIDAR device according to an embodiment of the present disclosure is shown. The order in which some or all of the process blocks in process 800 appear should not be considered limiting. Instead, one of ordinary skill in the art having benefit of the present disclosure will appreciate that some process blocks may be performed in a variety of orders not shown, or even in parallel.

[0212] In process block 805, a light source (eg, laser 202) is illuminated to generate a transmit beam. The transmit beam may be near infrared light.

[0213] In process block 810 , a transmit beam is selectively directed to a transmit antenna (eg, antenna 605 ) of a beam-transmitting LIDAR pixel among a plurality of LIDAR pixels.

[0214] In process block 815, the first local oscillator signal and the second local oscillator signal are selectively directed to the beam-transmitting LIDAR pixels while the transmit beam is selectively directed to the beam-transmitting LIDAR pixels.

[0215] In an embodiment of process 800, a first local oscillator signal is selectively directed to a first optical mixer of a beam-transmitting LIDAR pixel, and a second local oscillator signal is selectively directed to a second optical mixer of a beam-transmitting LIDAR pixel. The first local oscillator signal may be of a first polarization orientation, and the second local oscillator signal may be of a second polarization orientation different from the first polarization orientation.

[0216] The beam transmitting LIDAR pixel may include a receiving optical antenna to detect a return beam, and the first optical mixer may be configured to receive a first polarization orientation of the return beam. The second optical mixer may be configured to receive a second polarization orientation of the return beam.

[0217] In an embodiment, process 800 further includes (i) selectively directing the transmit beam to a second transmit antenna of a second beam-transmitting LIDAR pixel among the plurality of LIDAR pixels, and (ii) selectively directing the first local oscillator signal and the second local oscillator signal to the second beam-transmitting LIDAR pixel while selectively directing the transmit beam to the second beam-transmitting LIDAR pixel.

[0218] In an embodiment of process 800, the transmit beam is not steered to a transmit antenna of a beam-transmitting LIDAR pixel while the transmit beam is steered to a second transmit antenna of a second beam-transmitting LIDAR pixel, and the first local oscillator signal and the second local oscillator signal are not steered to the beam-transmitting LIDAR pixel while the first local oscillator signal and the second local oscillator signal are steered to the second beam-transmitting LIDAR pixel.

[0219] 5. Additional Implementation Methods of Continuous Wave Modulation and Quasi-Continuous Wave Modulation

[0220] Fig. 9 FIG. 1 shows a LIDAR system 1200 according to an embodiment of the present disclosure. The LIDAR system 1200 may be a LIDAR sensor 136 (eg, Figure 1A ) and LIDAR system 104B (as shown Figure 1B 1206, and a transceiver 1208. According to an embodiment of the present 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 transmit signal 1210. According to an embodiment, the beam splitter 1204 can split the transmit signal 1210 into transmit signals TX0-7 and local oscillator signals LO1 and LO2. The beam splitter 1204 can be configured to provide the transmit signals TX 0-7 and the local oscillator signals LO1 and LO2 to the transceiver 1208 at a plurality of input ports 1209. Alternatively, according to an embodiment of the present disclosure, the optical splitter 1204 can be coupled to the polarizer 1206 and configured to provide a first local oscillator signal 1224 and a second local oscillator signal 1226, and the polarizer 1206 converts 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 receive signals RXS0-7 and RXP0-7 from receive optical antennas configured to detect different polarizations.

[0221] In some embodiments, the transceiver 1208 can be configured to receive input signals (e.g., transmit signals TX0-7 and local oscillator signals LO1 and LO2), and can 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, the transceiver 1208 is configured to operate using one transmit signal TX0 and one local oscillator signal LO1. The transceiver 1208 can include a local oscillator network 1212 and a LIDAR pixel array 1214 configured to support scanning and imaging operations of an autonomous vehicle environment.

[0222] In some implementations, the local oscillator network 1212 can be configured to receive one or both of the local oscillator signals LO1 and LO2 and can be configured to distribute one or both of the 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 can include a plurality of waveguide channels coupled to provide the local oscillator signals LO1 and LO2 to the LIDAR pixel array 1214. The local oscillator network 1212 can be coupled to the LIDAR pixel array 1214 via one or both of the local oscillator buses 1216 and 1218.

[0223] 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 transmit signals 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 a return beam having a first polarization. The LIDAR pixel array 1214 may be configured to generate receive signals RXP0-7 from a return beam having a second polarization orientation. The LIDAR pixel array 1214 may provide receive signals RXS0-7 on a first return signal bus 1220, and may provide receive signals RXP0-7 on a second return signal bus 1222. The transceiver 1208 may be configured to provide receive signals RXS0-7 and RXP0-7 to a plurality of output ports 1228. According to an embodiment 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.

[0224] Although transceiver 1208 is described with eight transmit signals and 16 receive signals, it should be understood that fewer (eg, one or two) or more (eg, hundreds or thousands) transmit or receive signals may be used according to various embodiments of the present disclosure.

[0225] Fig. 10A An example of a simplified schematic diagram of a LIDAR transceiver 1300 is shown in accordance with an embodiment of the disclosure. The LIDAR transceiver 1300 includes a local oscillator network 1302 coupled to provide a local oscillator signal to a LIDAR pixel array 1304 in accordance with an embodiment of the disclosure.

[0226] In some embodiments, a local oscillator (LO) network 1302 may be coupled to one or more of the plurality of input ports 1306 via waveguides 1310 and 1312 to receive one or both of the local oscillator signals LO1 and LO2. According to embodiments of the present disclosure, the local oscillator network 1302 may be configured to provide the local oscillator signals LO1 and LO2 to one or more LIDAR pixels of the LIDAR pixel array 1304 to enable the LIDAR pixels to generate receive signals RXS0-7 and RXP0-7 and provide the signals to the plurality of output ports 1308.

[0227] In some embodiments, LIDAR pixel array 1304 may include a plurality of LIDAR pixels positioned along one or two dimensions of the LIDAR transceiver 1300 footprint. According to an embodiment, LIDAR pixel 1314 is an example of one or more of the LIDAR pixels of LIDAR pixel array 1304. According to an embodiment, LIDAR pixel 1314 may receive a transmit signal on port 1316, may receive a local oscillator signal LO1 on port 1318, and may receive a local oscillator signal LO2 on port 1320. According to an embodiment of the present 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 port 1322 and port 1324, respectively. In an embodiment, LIDAR pixel 1314 receives a transmit signal, receives a local oscillator signal, and provides a single receive signal.

[0228] According to an embodiment of the present disclosure, the LIDAR pixel 1314 may include an optical antenna array 1326, a receiver circuit system 1328, and an optical rotator 1330. The optical antenna array 1326 may include at least one transmit optical antenna configured to receive a transmit signal and transmit a transmit beam into the LIDAR environment. The optical antenna array 1326 may include a first receive optical antenna configured to detect a first polarization orientation of a return beam, may include a second receive optical antenna configured to detect a second polarization orientation of the return beam, or may include both the first receive optical antenna and the second receive optical antenna. The first polarization orientation may be orthogonal to the second polarization orientation. The receiver circuit system 1328 may be configured to convert an optical signal into an electrical signal, for example, a receive signal RXS and a receive signal RXP. The receiver circuit system 1328 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 1330 may be located between the optical antenna array 1326 and the receiver circuit system 1328. The optical rotator 1330 may be configured to provide a transmit signal to the optical antenna array 1326 and may be configured to provide a return signal from the return optical antenna to the receiver circuitry 1328 to support generation of receive signals RXS and RXP. The optical rotator 1330 may be implemented as a polarization beam splitter within a waveguide, but 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 photodiode).

[0229] In some embodiments, LIDAR transceiver 1300 may include an array of power monitors configured to detect the amount of power in each transmit signal provided to a LIDAR pixel of LIDAR pixel array 1304. The power monitor array may include one power monitor for each LIDAR pixel in LIDAR pixel array 1304. Power monitor 1332 may be an example of a power monitor of the power monitor array. Power monitor 1332 may include waveguide 1334, waveguide 1336, and photodiode 1338. The transmit signal may propagate through waveguide 1334, so waveguide 1334 may be positioned linearly with the transmit signal waveguide. Waveguide 1336 may be located near waveguide 1334 to receive a portion of the transmit signal. Photodiode 1338 may be coupled to waveguide 1336 and may be configured to convert a portion of the transmit signal into an electrical signal to support power monitoring operations. The LIDAR transceiver 1300 may include a plurality of output ports 1340 communicatively coupled to power monitors of the power monitor array and configured to provide power monitor outputs externally to the LIDAR transceiver 1300 .

[0230] According to an embodiment, LIDAR transceiver 1300 receives transmit signals (e.g., TX0, TX1, TX2, TX3, TX4, TX5, TX6, TX7, etc.) on some of ports 1306 coupled to LIDAR pixel array 1304 via a plurality of 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 may be implemented in LIDAR transceiver 1300 according to various embodiments of the present disclosure.

[0231] Fig. 10B A LIDAR transceiver 1350 is shown in accordance with an embodiment of the present disclosure. The LIDAR transceiver 1350 may include an optical splitter 1352 and an optical splitter 1354 configured to distribute a transmit signal from an input port 1306. The optical splitter 1352 and the optical splitter 1354 may be implemented as a passive optical splitter including a plurality of optical splitters configured to receive one optical signal and split the 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, the optical splitters 1352 and 1354 may be 1 to 4 optical splitters, or may be configured to split the transmit signal into many more signals (e.g., 8, 16, 32, 64, etc.). The use of the optical splitters 1352 and 1354 may reduce noise caused by crosstalk and may alleviate the burden associated with routing waveguides within the LIDAR transceiver 1350.

[0232] Fig.11 FIG. 1 shows a LIDAR system 1400 including a LIDAR pixel 1499 according to an embodiment of the present disclosure. The LIDAR pixel 1499 may include an optical antenna array 1460, which may be an optical antenna array 1326 (e.g., Fig. 10A and 10B 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 Fig.11The specific LIDAR pixel architecture shown. The LIDAR pixel can be implemented using any suitable chip design architecture. For example, the transmit and receive 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 transmit 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 be a single defined polarization orientation. According to an embodiment, in Fig.11 , the transmit 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 a waveguide 1403. The transmit signal 1401 can be generated by a laser, and the transmit beam emitted by the transmit optical antenna 1405 can have a very narrow line width (e.g., 1 nm or less).

[0233] In some embodiments, the receiving optical antenna 1410 can be a dual polarization receiving optical antenna configured to detect a first polarization orientation of a return beam and a second polarization orientation of the return beam. The return beam can be a reflection of a transmit 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 range higher 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-polarization and the second polarization orientation can be p-polarization, or vice versa. In Fig.11 , the receiving optical antenna 1410 includes a first single polarization grating coupler 1411 and a second single polarization grating coupler 1416. The first single polarization grating coupler 1411 can be configured to couple the first polarization orientation of the return beam to the first coherent receiver 1421 through the waveguide 1412. The second single polarization grating coupler 1416 can be configured to couple the second polarization orientation of the return beam to the second coherent receiver 1426 through the waveguide 1417. The transmitting optical antenna 1405 can transmit a transmit beam with a second polarization orientation (as shown in the figure), or can be configured to transmit a transmit beam with a first polarization orientation.

[0234] The first single polarization grating coupler 1411 can be rotated relative to the second single polarization grating coupler 1416. Fig.11In the specific implementation 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 transmit optical antenna 1405 can be rotated relative to the first single polarization grating coupler 1411 and can include a similar orientation as the second single polarization grating coupler 1416. Specifically, according to an implementation, the first single polarization grating coupler 1411 can be rotated +45 degrees, the transmit optical antenna 1405 can be rotated -45 degrees, and the second single polarization grating coupler 1416 can be rotated -45 degrees.

[0235] In some embodiments, the transmit optical antenna 1405, the first single polarization grating coupler 1411, and the second single polarization grating coupler 1416 can be positioned in a one-dimensional (1D) straight line to support receiving a return beam (e.g., from a rotating mirror) that may affect the optical antenna array 1460 at a location offset from the transmit optical antenna 405, for example, due to the transmit-receive property of transmitting and receiving LIDAR signals using a rotating mirror). For example, the first single polarization grating coupler 1411 can be offset from the transmit 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 transmit optical antenna 1405. The second single polarization grating coupler 1416 can be offset from the transmit optical antenna 1405 in the optical antenna array 1460 by a second distance D2. The first single polarization grating coupler 1411 can be offset from the second single polarization grating coupler 1416 by a third distance D3.

[0236] In some embodiments, the first coherent receiver 1421 can be configured to generate a first signal 1423 in response to receiving the first polarization orientation of the return beam and a first local oscillator signal 1431. The first local oscillator signal 1431 can be an optical signal having a first polarization orientation and can be a local oscillator signal LO1. Fig.11 , the first polarization orientation of the return beam can be received by the first coherent receiver 1421 from the first single polarization grating coupler 1411 through the waveguide 1412, and the first local oscillator signal 1431 can be received by the first coherent receiver 1421 through the waveguide 432. The first signal 1423 can be an electrical signal provided to the processing logic 1450 through the communication channel 1422.

[0237] In some embodiments, the first coherent receiver 1421 may include an optical mixer 1462 and a photodiode pair 1464 for converting a 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 a return 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 the communication channel 1422. The first signal 1423 may be an example of a received signal RXS (e.g., Fig. 10A and 10B The number of output signals of the optical mixer can be any suitable number and is not limited to a specific number.

[0238] In some embodiments, the second coherent receiver 1426 can be configured to generate a second signal 1428 in response to receiving the second polarization orientation of the return beam and the second local oscillator signal 1436. The second local oscillator signal 1436 can be an optical signal having a second polarization orientation and can be a local oscillator signal LO2. Fig.11 14, a second polarization orientation of the return beam can be received by the second coherent receiver 1426 from the second single polarization grating coupler 1416 through the waveguide 1417, and a second local oscillator signal 1436 is received by the second coherent receiver 1426 through the waveguide 1437. The second signal 1428 can be an electrical signal provided to the processing logic 1450 through the communication channel 1427.

[0239] In some embodiments, the second coherent receiver 1426 may include an optical mixer 1466 and a photodiode pair 1468 for converting a received optical signal into an electrical signal. The optical mixer 1466 may be coupled to receive the local oscillator signal LO2 and a signal representing a second polarization orientation of the return 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 the processing logic 1450 via the communication channel 1427. The second signal 1428 may be an example of a received signal RXP (e.g., Fig. 10A and 10B The number of output signals of the optical mixer can be any suitable number and is not limited to a specific number.

[0240] In some embodiments, the received optical signal, the transmit signal (before transmission), and the local oscillator signal can have the same polarization orientation when on the chip (e.g., when propagating through a waveguide). One or more of the optical antennas can be configured to change the polarization orientation (e.g., rotate) of the return beam and the transmit beam to one or more specific polarization orientations. For example, the optical antenna can be configured to convert a return beam having a first polarization orientation into a waveguide as a return signal having a second or third polarization orientation. As another example, the transmit signal can have a third orientation when in the waveguide, and the optical antenna can be configured to couple the transmit signal into free space as a transmit beam having the first or second polarization orientation.

[0241] The processing logic 1450 can be configured to generate an image 1455 in response to receiving the first signal 1423 and the second signal 1428 from the first coherent receiver 1421 and the second coherent receiver 1426, respectively. The LIDAR system 1400 may include a LIDAR pixel array 1499 configured to provide the first signal (e.g., signal 1423) and the second signal (e.g., signal 1428) to the processing logic 1450. In this context, the processing logic 1450 may generate the image 1455 in response to the first signal and the second signal received by the processing logic 1450 through a plurality of LIDAR pixels 1499 in the LIDAR pixel array.

[0242] In an example of operation, a transmit signal 1401 may be emitted as a transmit beam by a transmit optical antenna 1405 into free space. The transmit beam may pass through one or more lenses and be deflected by a rotating mirror, and then pass through the external environment until an object is encountered. A portion of the transmit beam that encounters the object may be reflected as a return beam toward the LIDAR system 1400 and the LIDAR pixel 1499. The return beam may be reflected from the rotating mirror and pass through one or more lenses, but may be offset relative to the transmit optical antenna 1405 due to the time difference in the mirror rotation. To compensate for the offset, components of the receive optical antenna 1410 may be offset from the transmit optical antenna 1405.

[0243] Fig. 12A and 12B A simplified block diagram of a LIDAR device with a stacked antenna configuration is shown in accordance with an embodiment of the present disclosure. Fig. 12A An example of a LIDAR device 1500 having a first semiconductor layer 1502 stacked on top of a second semiconductor layer 1504 is shown. The LIDAR device 1500 may include a transmitting optical antenna 1506 and a receiving optical antenna 1508. The transmitting optical antenna 1506 is a semiconductor layer of the transmitting optical antenna 1405 (e.g., Fig.11) and can be configured to transmit a transmit beam having a second polarization orientation. The receiving optical antenna 1508 can be a second single polarization grating coupler 1416 (as shown in Fig.11 The second semiconductor layer 1504 includes a second receiving optical antenna 1510, which can be a first single polarization grating coupler 1411 (such as Fig.11 1504 and 1505. The optical transmission layer 1504 may be an example embodiment of an optical transmission layer 1504 and ...

[0244] Fig.11 B shows an example of a LIDAR device 1550 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. 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 that are offset from each other and positioned to receive a LIDAR return beam that passes through the first semiconductor layer 1552.

[0245] The term "processing logic" in the present 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, a 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 the present disclosure.

[0246] The "memory" or "memories" described in this disclosure may include one or more volatile or non-volatile memory architectures. The "memory" or "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 disks (DVD), high-definition multimedia / data storage disks, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information for access by a computing device.

[0247] The network may include any network or network system, such as, but not limited to, a peer-to-peer network; a local area network (LAN); a wide area network (WAN); a public network such as the Internet; a private network; a cellular network; a wireless network; a wired network; a combination of wireless and wired networks; and a satellite network.

[0248] The communication channel may include or be routed through 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.

[0249] The computing device may include a desktop computer, a laptop computer, a tablet computer, a phablet, a smartphone, a feature phone, a server computer, or other device. The server computer may be located in a remote data center or stored locally.

[0250] 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 (e.g., computer) readable storage medium, which, when executed by a machine, causes the machine to perform the described operations. Additionally, the processes may be contained in hardware, such as an application specific integrated circuit ("ASIC") or other hardware.

[0251] 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, a network device, a personal digital assistant, a manufacturing tool, any device with 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), magnetic disk storage media, optical storage media, flash memory devices, etc.).

[0252] The above description of the embodiments of the present invention (including the description in the Abstract) is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Although specific embodiments and examples of the present invention are described herein for illustrative purposes, those skilled in the relevant art will recognize that various modifications are possible within the scope of the invention.

[0253] These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification. Instead, the scope of the invention is to be determined entirely by the following claims, which should be interpreted in accordance with established doctrines of claim interpretation.

Claims

1. A light detection and ranging (LIDAR) sensor system for a vehicle, the LIDAR sensor system comprising: a laser source configured to emit a laser beam; a beam splitter configured to split the laser beam into a transmit beam and a local oscillator signal; 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; Multiple LIDAR pixels; a transmit beam module configured to provide the transmit beam to only one LIDAR pixel of the plurality of LIDAR pixels at any given time; a local oscillator module coupled to the plurality of LIDAR pixels, the local oscillator module comprising 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; One or more processors configured to: (i) driving the transmit beam module to provide the transmit beam to a first LIDAR pixel among the plurality of LIDAR pixels; as well as (ii) driving the local oscillator module to provide the first local oscillator signal and the second local oscillator signal to the first LIDAR pixel; as well as A power monitor is coupled to the first LIDAR pixel, the power monitor being configured to detect an amount of power in the transmit beam provided to the first LIDAR pixel.

2. The LIDAR sensor system according to claim 1, wherein: The one or more processors are configured to drive the transmit beam module to provide the transmit beam to the 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 first LIDAR pixel.

3. The LIDAR sensor system according to any one of claims 1 or 2, wherein: The first LIDAR pixel comprises: a first optical antenna configured to transmit the transmit beam; a second optical antenna configured to detect a return beam; a first receiver configured to receive (i) the first polarization orientation of the return beam; and (ii) the first local oscillator signal from the local oscillator module; and A second receiver is configured to receive (i) a second polarization orientation of the return beam; and (ii) the second local oscillator signal from the local oscillator module.

4. The LIDAR sensor system according to claim 3, wherein: The second optical antenna includes a dual polarization receiving grating, and the dual polarization receiving grating is configured as: (i) directing the first polarization orientation of the return beam to the first receiver; as well as (ii) directing the second polarization orientation of the return beam to the second receiver.

5. The LIDAR sensor system according to any one of claims 3 or 4, wherein: The second optical antenna comprises: a first polarization receiving grating configured to direct the first polarization orientation of the return beam to the first receiver; and A second polarization receiving grating is configured to direct the second polarization orientation of the return beam to the second receiver, wherein the first polarization receiving grating is spaced apart from the second polarization receiving grating.

6. The LIDAR sensor system according to any one of claims 3 to 5, wherein: The first receiver comprises a first optical mixer, and wherein, The second receiver includes a second optical mixer.

7. The LIDAR sensor system according to any one of claims 1 to 6, wherein: The local oscillator module is configured to provide the first local oscillator signal and the second local oscillator signal to only one particular LIDAR pixel of the plurality of LIDAR pixels at any given time.

8. The LIDAR sensor system according to any one of claims 1 to 8, wherein: The first local oscillator signal has a first polarization orientation, and wherein, The second local oscillator signal has a second polarization orientation different from the first polarization orientation.

9. The LIDAR sensor system of claim 8, wherein: The first polarization orientation is orthogonal to the second polarization orientation.

10. The LIDAR sensor system according to any one of claims 1 to 9, wherein: At least one of the local oscillator module or the transmit beam module includes a plurality of optical switches in a multi-layer configuration.

11. The LIDAR sensor system of claim 10, wherein: The local oscillator module includes a first plurality of optical switches arranged in a first multi-layer configuration; and 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.

12. The LIDAR sensor system of claim 11, wherein: The first multi-layer configuration includes more switches than the second multi-layer configuration.

13. The LIDAR sensor system according to any one of claims 1 to 12, wherein: The power monitor includes a detector, wherein the power monitor further comprises a first waveguide through which the transmit beam passes and a second waveguide configured to receive a portion of the transmit beam from the first waveguide, and Wherein the detector is configured to convert the portion of the transmit beam into an electrical signal to support power monitoring.

14. An autonomous vehicle control system for an autonomous vehicle, the autonomous vehicle control system comprising a light detection and ranging (LIDAR) system according to any one of claims 1 to 13.

15. An autonomous vehicle comprising a Light Detection and Ranging (LIDAR) system according to any one of claims 1 to 13.

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