# US 12,111,420 B2 · Mirror with polarizing beam splitter for LIDAR system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,420 B2 - Document ID: US12111420B2 - Status: Granted - Kind: B2 - Application number: 16/942,028 - Filed: 2020-07-29 - Published: 2022-02-03 - Granted: 2024-10-08 - Earliest claimed: 2020-07-29 - Assignees: LG Innotek Co., Ltd. - Applicants: LG Innotek Co., Ltd. - Inventors: Ryan T. Davis; Mohamed S. Seghilani; Richard S. D'Alo - Web page: https://patentgrep.com/patent/US12111420B2 ## CPC - G01S 7/481: Constructional features, e.g. arrangements of optical elements - G01S 17/931: of land vehicles - G01S 7/4815: {using multiple transmitters} - G01S 7/4816: {of receivers alone} - G01S 7/4817: {relating to scanning} - G02B 27/10: Beam splitting or combining systems (polarising systems G02B27/28; mixing and splitting light signals using optical waveguides G02B6/28; {beam shaping, e.g. changing the cross-sectional area, by dividing or superposing multiple light beams G02B27/0905}) - G01S 17/93: for anti-collision purposes - 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 Systems, methods, and computer-readable media are disclosed for systems and methods for improved LIDAR return light capture efficiency. One example method may include emitting, by an emitter, a first light pulse in a first path. The example method may also include transmitting, by a polarizing beam splitter in the first path and aligned with an aperture of a reflective element, a portion of the first light pulse, wherein the reflective element is disposed of in the first path. The example method may also include reflecting, by a reflective surface of the reflective element, a second light pulse in a second path, the second light pulse including a return pulse based on the first light pulse being reflected from an object. The example method may also include detecting, by a detector, the detector disposed in the second path of the second light pulse. ## Claims ### Claim 1 A system, comprising: an emitter configured to emit a first light pulse in a first path; a reflective element disposed in the first path of the first light pulse, the reflective element comprising: a polarizing beam splitter in the first path and aligned with an aperture of the reflective element, the polarizing beam splitter configured to pass a portion of the first light pulse; a reflective surface configured to reflect a second light pulse in a second path, the second light pulse including a return pulse based on the first light pulse being reflected from an object; an anti-reflection layer on a first surface of the reflective surface, the first surface facing the emitter; and a detector, the detector disposed in the second path of the second light pulse, wherein a size of the polarizing beam splitter is smaller than a size of the reflective surface, wherein a shape of the reflective element has a circular shape, wherein a shape of the aperture is different from the shape of the reflective element, and wherein at least one of the polarizing beam splitter and the anti-reflection layer is a coating on a base layer of the reflective element. ### Claim 2 (depends on 1) The system of claim 1, wherein the polarizing beam splitter is further configured to reflect at least a first portion of the return pulse of a first polarization towards the detector, and transmit a second portion of the return pulse of a second polarization. ### Claim 3 (depends on 1) The system of claim 1, further comprising: a first lens disposed between the emitter and reflective element in the first path of the first light pulse; and a second lens disposed between the reflective element and the detector in the second path of the second light pulse. ### Claim 4 (depends on 1) The system of claim 1, wherein the polarizing beam splitter is at least partially disposed in the aperture. ### Claim 5 (depends on 1) The system of claim 1, wherein the reflective surface comprises a layer of reflective material disposed on a first surface of the reflective element, the layer of reflective material exposing a portion of the polarizing beam splitter approximate the aperture. ### Claim 6 (depends on 1) The system of claim 1, wherein the shape of the aperture defined by the reflective element is oval. ### Claim 7 (depends on 6) The system of claim 6, wherein a wall of the reflective element defining the aperture is parallel to the first path and perpendicular to the second path, and wherein an outer surface of the reflective element has a slope between the first path and the second path. ### Claim 8 (depends on 1) The system of claim 1, wherein a diameter of the aperture is approximately a size of a width of the first light pulse. ### Claim 9 A reflective apparatus for an optical system, comprising: a planar structure having a first surface and a substantially parallel second surface, the planar structure defining an aperture, wherein the aperture extends from the first surface to the second surface and is in a first path of a first light pulse; and a polarizing beam splitter disposed in the aperture, the polarizing beam splitter configured to pass a portion of the first light pulse, wherein the first surface includes a reflective surface configured to reflect a second light pulse in a second path, the second light pulse including a return pulse based on the first light pulse being reflected from an object, wherein the second surface includes an anti-reflection layer, wherein a size of the polarizing beam splitter is smaller than a size of the reflective surface, wherein a shape of the planar structure has a circular shape, wherein a shape of the aperture is different from the shape of the planar structure, and wherein at least one of the polarizing beam splitter and the anti-reflection layer is a coating on a base layer of the reflective element. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the polarizing beam splitter is further configured to reflect at least a first portion of the return pulse of a first polarization towards a detector of the optical system, and transmit a second portion of the return pulse of a second polarization. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the reflective surface is on the base layer. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein the shape of the aperture defined by the reflective apparatus is oval. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein a wall of the reflective apparatus defining the aperture is parallel to the first path and perpendicular to the second path, and wherein an outer surface of the reflective apparatus has a slope between the first path and the second path. ### Claim 14 (depends on 9) The apparatus of claim 9, wherein a width of the aperture is approximately a size of the width of the first light pulse. ### Claim 15 A method comprising; emitting, by an emitter, a first light pulse in a first path; transmitting, by a polarizing beam splitter in the first path and aligned with an aperture of a reflective element, a portion of the first light pulse, wherein the reflective element is disposed of in the first path; reflecting, by a reflective surface of the reflective element, a second light pulse in a second path, the second light pulse including a return pulse based on the first light pulse being reflected from an object, wherein a size of the polarizing beam splitter is smaller than a size of the reflective surface; detecting, by a detector, the second light pulse, the detector disposed in the second path of the second light pulse; and providing an anti-reflection layer opposite the reflective surface, wherein a shape of the reflective element has a circular shape, wherein a shape of the aperture is different from the shape of the reflective element, and wherein at least one of the polarizing beam splitter and the anti-reflection layer is a coating on a base layer of the reflective element. ### Claim 16 (depends on 15) The method of claim 15, wherein the polarizing beam splitter is further configured to reflect at least a first portion of the return pulse of a first polarization towards the detector, and transmit a second portion of the return pulse of a second polarization. ### Claim 17 (depends on 15) The method of claim 15, wherein the polarizing beam splitter is disposed in the aperture of the reflective surface or the polarizing beam splitter and reflective surface are one or more layers of material disposed on the reflective element. ### Claim 18 (depends on 15) The method of claim 15, wherein the aperture defined by the reflective element is oval. ### Claim 19 (depends on 18) The method of claim 18, wherein a wall of the reflective element defining the aperture is parallel to the first path and perpendicular to the second path, and wherein an outer surface of the reflective element has a slope between the first path and the second path. ### Claim 20 (depends on 1) The system of claim 1, wherein the anti-reflection layer is disposed on the base layer.