# US 12,111,422 B2 · Array of waveguide diffusers for light detection using an aperture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,422 B2 - Document ID: US12111422B2 - Status: Granted - Kind: B2 - Application number: 18/333,074 - Filed: 2023-06-12 - Published: 2023-10-12 - Granted: 2024-10-08 - Earliest claimed: 2016-12-01 - Assignees: Waymo LLC - Applicants: Waymo LLC - Inventors: Pierre-Yves Droz; David Hutchison - Web page: https://patentgrep.com/patent/US12111422B2 ## CPC - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - G01S 7/4813: {Housing arrangements} - G01S 7/4816: {of receivers alone} - G01S 7/4817: {relating to scanning} - G01S 7/4818: {using optical fibres} - G01S 7/4865: Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak (peak detection in noise, signal conditioning G01S7/487) - G01S 17/00: Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems - G01S 17/89: for mapping or imaging - G02B 5/003: {Light absorbing elements} - G02B 5/005: {Diaphragms (for cameras G03B9/02)} - G02B 6/08: with fibre bundle in form of plate - G02B 19/0014: {at least one surface having optical power} - G02B 19/0076: {for use with a detector (G02B19/009, G02B19/0095 take precedence)} - G02B 27/0994: {Fibers, light pipes (optical fibers per se G02B6/02)} - G01S 17/931: of land vehicles - 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 - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present disclosure relates to limitation of noise on light detectors using an aperture. One example implementation includes a system. The system includes a lens that focuses light from a scene toward a focal plane. The system also includes an aperture defined within an opaque material. The system also includes a plurality of waveguides. A given waveguide of the plurality has an input end that receives a portion of light transmitted through the aperture, and guides the received portion toward an output end of the given waveguide. A cross-sectional area of the guided portion at the output end is greater than a cross-sectional area of the received portion at the input end. The system also includes an array of light detectors that detects the guided light transmitted through the output end. ## Claims ### Claim 1 A system comprising: an aperture defined within an opaque material; a lens configured to focus light from a scene toward the aperture, such that the light from the scene is transmitted through the aperture; a plurality of waveguides optically coupled to the lens via the aperture, the plurality of waveguides including at least a first waveguide configured to receive a first portion of the light transmitted through the aperture and a second waveguide configured to receive a second portion of the light transmitted through the aperture, wherein the first waveguide has a first input end and a first output end and is configured to receive the first portion of the light transmitted through the aperture at the first input end and guide the received first portion toward the first output end by total internal reflection, and wherein the second waveguide has a second input end and a second output end and is configured to receive the second portion of the light transmitted through the aperture at the second input end and guide the received second portion toward the second output end by total internal reflection; a first light detector array optically coupled to the first waveguide, wherein the first waveguide is configured to guide the received first portion toward the first light detector array; and a second light detector array optically coupled to the second waveguide, wherein the second waveguide is configured to guide the received second portion toward the second light detector array. ### Claim 2 (depends on 1) The system of claim 1, wherein the aperture is disposed along a focal plane of the lens. ### Claim 3 (depends on 1) The system of claim 1, wherein the first and second waveguides are arranged relative to a focal plane of the lens such that: the received first portion diverges inside the first waveguide and propagates out of the first output end as a first diverging light portion; and the received second portion diverges inside the second waveguide and propagates out of the second output end as a second diverging light portion. ### Claim 4 (depends on 3) The system of claim 3, wherein: the first light detector array is configured to intercept and detect the first diverging light portion; and the second light detector array is configured to intercept and detect the second diverging light portion. ### Claim 5 (depends on 4) The system of claim 4, wherein: the first diverging light portion detected at the first light detector array has a cross-sectional area that is greater than a cross-sectional area of the first received portion at the first input end; and the second diverging light portion detected at the second light detector array has a cross-sectional area that is greater than a cross-sectional area of the second received portion at the second input end. ### Claim 6 (depends on 1) The system of claim 1, wherein: the first light detector array comprises a first plurality of single photon avalanche diodes (SPADs); and the second light detector array comprises a second plurality of SPADs. ### Claim 7 (depends on 1) The system of claim 1, wherein: the first light detector array is configured to detect a first range of wavelengths; and the second light detector array is configured to detect a second range of wavelengths, wherein the second range of wavelengths is different than the first range of wavelengths. ### Claim 8 (depends on 1) The system of claim 1, further comprising: an optical filter disposed in an optical path between the lens and the first light detector array, wherein the optical filter is configured to selectively transmit light within a predefined wavelength range. ### Claim 9 (depends on 1) The system of claim 1, further comprising: a third light detector array optically coupled to a third waveguide in the plurality of waveguides, wherein the third waveguide is configured to receive a third portion of the light transmitted through the aperture and guide the received third portion toward the third light detector array. ### Claim 10 A light detection and ranging (LIDAR) device comprising: a LIDAR transmitter that illuminates a scene; a LIDAR receiver that receives light from the scene, wherein the light from the scene comprises light scattered by one or more objects within the scene, wherein the LIDAR receiver comprises: an aperture defined within an opaque material; a lens configured to focus the light from the scene toward the aperture, such that the light from the scene is transmitted through the aperture; a plurality of waveguides optically coupled to the lens via the aperture, the plurality of waveguides including at least a first waveguide configured to receive a first portion of the light transmitted through the aperture and a second waveguide configured to receive a second portion of the light transmitted through the aperture, wherein the first waveguide has a first input end and a first output end and is configured to receive the first portion of the light transmitted through the aperture at the first input end and guide the received first portion toward the first output end by total internal reflection, and wherein the second waveguide has a second input end and a second output end and is configured to receive the second portion of the light transmitted through the aperture at the second input end and guide the received second portion toward the second output end by total internal reflection; a first light detector array optically coupled to the first waveguide, wherein the first waveguide is configured to guide the received first portion toward the first light detector array; and a second light detector array optically coupled to the second waveguide, wherein the second waveguide is configured to guide the received second portion toward the second light detector array. ### Claim 11 (depends on 10) The LIDAR device of claim 10, wherein the first and second waveguides are arranged relative to a focal plane of the lens such that: the received first portion diverges inside the first waveguide and propagates out of the first output end as a first diverging light portion; and the received second portion diverges inside the second waveguide and propagates out of the second output end as a second diverging light portion. ### Claim 12 (depends on 11) The LIDAR device of claim 11, wherein: the first light detector array is configured to intercept and detect the first diverging light portion; and the second light detector array is configured to intercept and detect the second diverging light portion. ### Claim 13 (depends on 12) The LIDAR device of claim 12, wherein: the first diverging light portion detected at the first light detector array has a cross-sectional area that is greater than a cross-sectional area of the first received portion at the first input end; and the second diverging light portion detected at the second light detector array has a cross-sectional area that is greater than a cross-sectional area of the second received portion at the second input end. ### Claim 14 (depends on 10) The LIDAR device of claim 10, wherein: the first light detector array comprises a first plurality of single photon avalanche diodes (SPADs); and the second light detector array comprises a second plurality of SPADs. ### Claim 15 (depends on 10) The LIDAR device of claim 10, wherein: the first light detector array is configured to detect a first range of wavelengths; and the second light detector array is configured to detect a second range of wavelengths, wherein the second range of wavelengths is different than the first range of wavelengths. ### Claim 16 (depends on 10) The LIDAR device of claim 10, further comprising: an optical filter disposed in an optical path between the lens and the first light detector array, wherein the optical filter is configured to selectively transmit light within a predefined wavelength range. ### Claim 17 A method comprising: focusing, by a lens, light from a scene toward an aperture defined within an opaque material, such that the light from the scene is transmitted through the aperture; receiving, at a first waveguide, a first portion of the light transmitted through the aperture, wherein the first waveguide has a first input end and a first output end; guiding, by the first waveguide, the received first portion from the first input end toward the first output end by total internal reflection and toward a first light detector array; receiving, at a second waveguide, a second portion of the light transmitted through the aperture, wherein the second waveguide has a second input end and a second output end; guiding, by the second waveguide, the received second portion from the second input end toward the second output end by total internal reflection and toward a second light detector array. ### Claim 18 (depends on 17) The method of claim 17, further comprising: detecting, by the first light detector array, a first diverging light portion, wherein the first diverging light portion comprises light from the first received portion that has diverged inside the first waveguide and propagated out of the first output end of the first waveguide; and detecting, by the second light detector array, a second diverging light portion, wherein the second diverging light portion comprises light from the second received portion that has diverged inside the second waveguide and propagated out of the second output end of the first waveguide. ### Claim 19 (depends on 18) The method of claim 18, wherein: the first diverging light portion detected at the first light detector array has a cross-sectional area that is greater than a cross-sectional area of the first received portion at the first input end; and the second diverging light portion detected at the second light detector array has a cross-sectional area that is greater than a cross-sectional area of the second received portion at the second input end. ### Claim 20 (depends on 17) The method of claim 17, wherein: the first light detector array is configured to detect a first range of wavelengths; and the second light detector array is configured to detect a second range of wavelengths, wherein the second range of wavelengths is different than the first range of wavelengths.