# US 11,906,668 B2 · Light detection and ranging (LiDAR) system using a wavelength converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,668 B2 - Document ID: US11906668B2 - Status: Granted - Kind: B2 - Application number: 17/513,563 - Filed: 2021-10-28 - Published: 2022-02-17 - Granted: 2024-02-20 - Earliest claimed: 2018-08-14 - Assignees: Beijing Voyager Technology Co., Ltd. - Applicants: Beijing Voyager Technology Co., Ltd. - Inventors: Chao Wang; Youmin Wang; Yue Lu; Lingkai Kong - Web page: https://patentgrep.com/patent/US11906668B2 ## CPC - G01S 7/484: Transmitters - G01S 7/4815: {using multiple transmitters} - G01S 7/4817: {relating to scanning} - 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 - G02F 1/353: {Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams} - G02F 1/3551: {Crystals} - G02F 1/37: for second-harmonic generation {(G02F1/3532 takes precedence)} - H01S 3/0092: {Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35)} - H01S 3/067: Fibre lasers - H01S 3/2375: {Hybrid lasers (H01S3/07 takes precedence)} - H01S 3/2391: {emitting at different wavelengths} - G02F 1/354: {Third or higher harmonic generation} - G02F 2201/02: fibre - 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 - 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 - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract Embodiments of the disclosure provide an apparatus for emitting laser light and a system and method for detecting laser light returned from an object. The system includes a transmitter and a receiver. The transmitter includes one or more laser sources, at least one of the laser sources configured to provide a respective native laser beam having a wavelength above 1,100 nm. The transmitter also includes a wavelength converter configured to receive the native laser beams provided by the laser sources and convert the native laser beams into a converted laser beam having a wavelength below 1,100 nm. The transmitter further includes a scanner configured to emit the converted laser beam to the object in a first direction. The receiver is configured to detect a returned laser beam having a wavelength below 1,100 nm and returned from the object in a second direction. ## Claims ### Claim 1 An optical sensing system, comprising: a transmitter, comprising: a first laser source configured to provide a first laser beam having a first wavelength above 1,100 nm; a second laser source configured to provide a second laser beam having a second wavelength different than the first wavelength; and a wavelength converter configured to convert the first laser beam and the second laser beam into a converted laser beam having a third wavelength below 1,100 nm, wherein the wavelength converter comprises: a nonlinear optical material configured to perform optical frequency mixing of the first laser beam and the second laser beam, and a temperature controller configured to set a temperature of the nonlinear optical material based on the third wavelength of the converted laser beam, wherein the first laser source and the second laser source are separate. ### Claim 2 (depends on 1) The optical sensing system of claim 1, wherein one of the first laser source or the second laser source is a fiber laser. ### Claim 3 (depends on 2) The optical sensing system of claim 2, wherein both the first laser source and the second laser source are fiber lasers. ### Claim 4 (depends on 1) The optical sensing system of claim 1, further comprising: a scanner configured to steer the converted laser beam towards an environment in a first direction; and a receiver configured to: detect a returned laser beam having a fourth wavelength below 1,100 nm returned from the environment in a second direction, wherein the receiver includes a silicon-based photodetector. ### Claim 5 (depends on 1) The optical sensing system of claim 1, wherein the nonlinear optical material includes a nonlinear optical crystal. ### Claim 6 (depends on 1) The optical sensing system of claim 1, further comprising: a third laser source configured to emit a third laser beam having a fifth wavelength, wherein the third laser source is separate from the first laser source and the second laser source. ### Claim 7 (depends on 6) The optical sensing system of claim 6, wherein the third wavelength of the converted laser beam is determined by 1 λ 4 = 1 λ 1 + 1 λ 2 + 1 λ 3 , where λ4 represents the third wavelength of the converted laser beam, λ1 represents the first wavelength of the first laser beam, λ2 represents the second wavelength of the second laser beam, and λ3 represents the fifth wavelength of the third laser beam, wherein at least one of λ1, λ2, or λ3 has a positive weight. ### Claim 8 (depends on 7) The optical sensing system of claim 7, wherein at least one of λ1, λ2, and λ3 has a negative weight. ### Claim 9 (depends on 8) The optical sensing system of claim 8, wherein one of λ1, λ2, and λ3 has a negative weight. ### Claim 10 (depends on 1) The optical sensing system of claim 1, wherein the third wavelength of the converted laser beam is determined by 1 λ ⁢ 3 = 1 λ ⁢ 1 + 1 λ ⁢ 2 where λ3 represents the third wavelength of the converted laser beam, λ1 represents the first wavelength of the first laser beam, and λ2 represents the second wavelength of the second laser beam. ### Claim 11 An apparatus for emitting laser light, comprising: a first laser source configured to provide a first laser beam having a first wavelength equal to or above 1,100 nm; a second laser source configured to provide a second laser beam having a second wavelength different than the first wavelength; and a wavelength converter configured to convert the first laser beam and the second laser beam into a converted laser beam having a third wavelength below 1,100 nm, wherein the wavelength converter comprises: a nonlinear optical material configured to perform optical frequency mixing of the first laser beam and the second laser beam, and a temperature controller configured to set a temperature of the nonlinear optical material based on the third wavelength of the converted laser beam, wherein the first laser source and the second laser source are separate. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the nonlinear optical material includes a nonlinear optical crystal. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein the third wavelength of the converted laser beam is determined by 1 λ ⁢ 3 = 1 λ ⁢ 1 + 1 λ ⁢ 2 where λ3 represents the third wavelength of the converted laser beam, λ1 represents the first wavelength of the first laser beam, and λ2 represents the second wavelength of the second laser beam. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein the first wavelength is equal to 1,100 nm. ### Claim 15 An optical sensing method, comprising: emitting, by a first laser source, a first laser beam having a first wavelength equal to or above 1,100 nm; emitting, by a second laser source, a second laser beam having a second wavelength different than the first wavelength; and converting, by a wavelength converter, the first laser beam and the second laser beam into a converted laser beam having a third wavelength below 1,100 nm, wherein the converting the first laser beam and the second laser beam into the converted laser beam comprises: setting, by a temperature controller, a temperature of a nonlinear optical material based on the third wavelength of the converted laser beam, and performing, by the nonlinear optical material, optical frequency mixing of the first laser beam and the second laser beam, wherein the first laser source and the second laser source are separate. ### Claim 16 (depends on 15) The method of claim 15, wherein the nonlinear optical material includes a nonlinear optical crystal. ### Claim 17 (depends on 15) The method of claim 15, wherein the third wavelength of the converted laser beam is determined by 1 λ ⁢ 3 = 1 λ ⁢ 1 + 1 λ ⁢ 2 where λ3 represents the third wavelength of the converted laser beam, λ1 represents the first wavelength of the first laser beam, and λ2 represents the second wavelength of the second laser beam.