# US 12,181,606 B2 · LIDAR pixel with active polarization control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,606 B2 - Document ID: US12181606B2 - Status: Granted - Kind: B2 - Application number: 17/870,493 - Filed: 2022-07-21 - Published: 2022-11-17 - Granted: 2024-12-31 - Earliest claimed: 2020-06-12 - Assignees: Aurora Operations, Inc. - Applicants: Aurora Operations, Inc. - Inventors: Andrew Steil Michaels; Sen Lin - Web page: https://patentgrep.com/patent/US12181606B2 ## CPC - G01S 7/4814: {of transmitters alone} - G01S 17/34: using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal - B60W 60/001: {Planning or execution of driving tasks} - G01S 7/4811: {common to transmitter and receiver} - G01S 7/4911: Transmitters - G01S 7/4918: {Controlling received signal intensity, gain or exposure of sensor} - G01S 7/493: Extracting wanted echo signals - G01S 7/499: using polarisation effects - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - G01S 17/894: Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar - G01S 17/931: of land vehicles - G02F 1/0136: {for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence)} - B60W 2420/408: Radar; Laser, e.g. lidar - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A light detection and ranging (LIDAR) pixel includes a splitter, a grating coupler, and a phase shifter. The grating coupler is configured to emit a transmit beam that is based on a combination of a first portion of light and a second portion of light received from a laser. One or more first interconnects and one or more second interconnects couple the splitter to the grating coupler. The phase shifter is coupled to the one or more first interconnects and configured to vary a phase of the first portion of the light relative to a phase of the second portion of the light. ## Claims ### Claim 1 A light detection and ranging (LIDAR) system comprising: a laser configured to generate light; and one or more LIDAR pixels, wherein at least one of the one or more LIDAR pixels includes: a splitter configured to split the light into a first portion of the light and a second portion of the light; a grating coupler configured to emit a transmit beam that is based on a combination of the first portion of the light and the second portion of the light; one or more first interconnects configured to provide the first portion of the light from the splitter to the grating coupler; one or more second interconnects configured to provide the second portion of the light from the splitter to the grating coupler; and a phase shifter coupled to the one or more first interconnects and configured to vary a phase of the first portion of the light relative to a phase of the second portion of the light, wherein the phase of the first portion of the light is selected from a plurality of greater than two different phase values. ### Claim 2 (depends on 1) The LIDAR system of claim 1 further comprising: an optical mixer configured to receive a third portion of the light originating from the laser, wherein the grating coupler is configured to couple reflected light having a first polarization orientation into the one or more first interconnects and configured to couple the reflected light having a second polarization orientation into the one or more second interconnects, wherein the optical mixer is configured to output an output signal in response to the reflected light, wherein the reflected light is the transmit beam reflected from at least one object in a LIDAR operating environment. ### Claim 3 (depends on 2) The LIDAR system of claim 2, wherein the splitter is coupled to the optical mixer to provide the reflected light to the optical mixer. ### Claim 4 (depends on 2) The LIDAR system of claim 2, wherein the splitter is first 2×2 splitter, wherein the at least one of the one or more LIDAR pixels further includes a second 2×2 splitter, wherein the second 2×2 splitter is coupled between the first 2×2 splitter and the grating coupler with the one or more first interconnects and the one or more second interconnects. ### Claim 5 (depends on 2) The LIDAR system of claim 2, wherein a polarization of the reflected light is at least partially based on one or more surfaces of the at least one object. ### Claim 6 (depends on 1) The LIDAR system of claim 1, wherein the one or more first interconnects are coupled between the splitter and the grating coupler, wherein the one or more second interconnects are coupled between the splitter and the grating coupler, wherein the phase shifter is coupled to the one or more first interconnects between the splitter and the grating coupler. ### Claim 7 (depends on 1) The LIDAR system of claim 1, wherein the grating coupler is a dual-polarization grating coupler, wherein the transmit beam includes a first transmit beam having a first polarization orientation and a second transmit beam having a second polarization orientation. ### Claim 8 (depends on 7) The LIDAR system of claim 7, wherein the first polarization orientation of the first transmit beam is orthogonal to the second polarization orientation of the second transmit beam. ### Claim 9 An autonomous vehicle control system for an autonomous vehicle, the autonomous vehicle control system comprising: a laser configured to generate light; a light detection and ranging (LIDAR) processing engine; and one or more LIDAR pixels coupled to the LIDAR processing engine, wherein at least one of the one or more LIDAR pixels includes: a splitter configured to split the light into a first portion of the light and a second portion of the light; a grating coupler configured to emit a transmit beam that is based on a combination of the first portion of the light and the second portion of the light; one or more first interconnects configured to provide the first portion of the light from the splitter to the grating coupler; one or more second interconnects configured to provide the second portion of the light from the splitter to the grating coupler; and a phase shifter coupled to the one or more first interconnects and configured to vary a phase of the first portion of the light relative to a phase of the second portion of the light, wherein the phase of the first portion of the light is selected from a plurality of greater than two different phase values. ### Claim 10 (depends on 9) The autonomous vehicle control system of claim 9 further comprising: an optical mixer configured to receive a third portion of the light originating from the laser, wherein the grating coupler is configured to couple reflected light having a first polarization orientation into the one or more first interconnects and configured to couple the reflected light having a second polarization orientation into the one or more second interconnects, wherein the optical mixer is configured to output an output signal in response to the reflected light, wherein the reflected light is the transmit beam reflected from at least one object in a LIDAR operating environment. ### Claim 11 (depends on 10) The autonomous vehicle control system of claim 10, wherein the splitter is coupled to the optical mixer to provide the reflected light to the optical mixer. ### Claim 12 (depends on 10) The autonomous vehicle control system of claim 10, wherein the splitter is first 2×2 splitter, wherein the at least one of the one or more LIDAR pixels further includes a second 2×2 splitter, wherein the second 2×2 splitter is coupled between the first 2×2 splitter and the grating coupler with the one or more first interconnects and the one or more second interconnects. ### Claim 13 (depends on 12) The autonomous vehicle control system of claim 12, wherein the phase shifter is a first phase shifter coupled between the first 2×2 splitter and the second 2×2 splitter, wherein the at least one of the one or more LIDAR pixels further includes a second phase shifter coupled to the one or more first interconnects, wherein the second phase shifter is coupled between the second 2×2 splitter and the grating coupler. ### Claim 14 (depends on 10) The autonomous vehicle control system claim 10, wherein a polarization of the reflected light is at least partially based on one or more surfaces of the at least one object. ### Claim 15 (depends on 9) The autonomous vehicle control system of claim 9, wherein the grating coupler is a dual-polarization grating coupler, wherein the transmit beam includes a first transmit beam having a first polarization orientation and a second transmit beam having a second polarization orientation. ### Claim 16 (depends on 15) The autonomous vehicle control system of claim 15, wherein the first polarization orientation of the first transmit beam is orthogonal to the second polarization orientation of the second transmit beam. ### Claim 17 (depends on 9) The autonomous vehicle control system of claim 9, wherein the LIDAR processing engine is configured to control the phase shifter to increase a signal level a beat signal that is based on returning light coupled into the at least one of the one or more LIDAR pixels by the grating coupler. ### Claim 18 (depends on 9) The autonomous vehicle control system of claim 9, wherein the transmit beam is an infrared output beam. ### Claim 19 An autonomous vehicle comprising: a laser configured to generate light; a light detection and ranging (LIDAR) processing engine; one or more LIDAR pixels coupled to the LIDAR processing engine, wherein at least one of the one or more LIDAR pixels includes: a splitter configured to split the light into a first portion of the light and a second portion of the light; a grating coupler configured to emit a transmit beam that is based on a combination of the first portion of the light and the second portion of the light; one or more first interconnects configured to provide the first portion of the light from the splitter to the grating coupler, one or more second interconnects configured to provide the second portion of the light from the splitter to the grating coupler; and a phase shifter coupled to the one or more first interconnects and configured to vary a phase of the first portion of the light relative to a phase of the second portion of the light, wherein the phase of the first portion of the light is selected from a plurality of greater than two different phase values; and one or more processors configured to control the autonomous vehicle based on a return signal received by the at least one of the one or more LIDAR pixels. ### Claim 20 (depends on 19) The autonomous vehicle of claim 19 further comprising: an optical mixer configured to receive a third portion of the light originating from the laser, wherein the grating coupler is configured to couple reflected light having a first polarization orientation into the one or more first interconnects and configured to couple the reflected light having a second polarization orientation into the one or more second interconnects, wherein the optical mixer is configured to output the return signal in response to the reflected light, wherein the reflected light is the transmit beam reflected from at least one object in a LIDAR operating environment.