# US 12,224,547 B2 · Laser device and method of using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,547 B2 - Document ID: US12224547B2 - Status: Granted - Kind: B2 - Application number: 17/651,350 - Filed: 2022-02-16 - Published: 2023-05-18 - Granted: 2025-02-11 - Earliest claimed: 2021-11-16 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Taiwan Semiconductor Manufacturing Company, Ltd. - Inventors: Yu-Hua Hsieh; Ying-Yen Tseng; Wen-Yu Ku; Kei-Wei Chen - Web page: https://patentgrep.com/patent/US12224547B2 ## CPC - H01S 3/082: defining a plurality of resonators, e.g. for mode selection or suppression - G01B 11/303: {using photoelectric detection means} - 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 3/08059: {Constructional details of the reflector, e.g. shape (mirrors in general G02B5/08; mountings for mirrors G02B7/18)} - H01S 3/108: using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering {(mode locking using a non-linear element H01S3/1112)} - H01S 3/1123: Q-switching - H01S 3/10061: {Polarization control} - 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 - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract Some implementations described herein provide a laser device. The laser device includes a first portion of the laser device, at a proximal end of the laser device, that includes one or more optical devices, where the first portion is configured to emit first electromagnetic waves having a first wavelength. The laser device includes a second portion of the laser device, at a distal end of the laser device, that includes an optical crystal configured to receive the first electromagnetic waves and to emit second electromagnetic waves having a second wavelength based on reception of the first electromagnetic waves, where the optical crystal includes a thin film coating disposed on an end of the optical crystal, the thin film coating configured to: support emission of the second electromagnetic waves from the optical crystal, and support internal reflection of the first electromagnetic waves within the optical crystal. ## Claims ### Claim 1 A laser device, comprising: a first optical crystal, at a proximal end of the laser device, configured to emit first electromagnetic waves having a first wavelength; and a second optical crystal, at a distal end of the laser device, configured to receive the first electromagnetic waves and to emit second electromagnetic waves having a second wavelength based on reception of the first electromagnetic waves, wherein the second optical crystal comprises: a first end having a thin film coating disposed thereon, and a second end comprising two angled surfaces that each has a reflective film disposed thereon, wherein the two angled surfaces are formed with angles that are symmetric about a logical axis that is parallel to a transmission path in a direction from the proximal end of the laser device to the distal end of the laser device. ### Claim 2 (depends on 1) The laser device of claim 1, wherein the first optical crystal is further configured to generate the first electromagnetic waves. ### Claim 3 (depends on 1) The laser device of claim 1, further comprising: a modulator device, at the proximal end of the laser device, configured to modulate the first electromagnetic waves before providing the first electromagnetic waves to the second optical crystal. ### Claim 4 (depends on 3) The laser device of claim 3, wherein to modulate the first electromagnetic waves, the modulator device is configured to: form pulses of the first electromagnetic waves based on a control signal. ### Claim 5 (depends on 1) The laser device of claim 1, wherein the second end of the second optical crystal comprises a second thin film coating disposed thereon, wherein the second thin film coating is configured to: support reception of the first electromagnetic waves into the second optical crystal, and support internal reflection of the second electromagnetic waves within the second optical crystal. ### Claim 6 (depends on 1) The laser device of claim 1, wherein the first end of the second optical crystal is proximate to the first optical crystal, and wherein the second end of the second optical crystal is opposite from the first end of the second optical crystal. ### Claim 7 (depends on 1) The laser device of claim 1, wherein the thin film coating is configured to support emission of the second electromagnetic waves from the second optical crystal and to support internal reflection of the first electromagnetic waves within the second optical crystal based on: the first wavelength, the second wavelength, a material of the thin film coating, and a thickness of the thin film coating. ### Claim 8 (depends on 1) The laser device of claim 1, wherein the distal end of the laser device is free from a mirror device disposed along a transmission path of the second electromagnetic waves after emission from the second optical crystal. ### Claim 9 (depends on 1) The laser device of claim 1, wherein the reflective film of each of the two angled surfaces of the second end is configured to support internal reflection of the first electromagnetic waves and the second electromagnetic waves. ### Claim 10 (depends on 1) The laser device of claim 1, wherein the first electromagnetic waves is received by the second optical crystal from a first direction, and wherein the second electromagnetic waves is emitted by the second optical crystal in a second direction that is different from the first direction. ### Claim 11 (depends on 10) The laser device of claim 10, further comprising: a beam splitter, at a distal end of the laser device, configured to reflect a portion of the second electromagnetic waves, after emission by the second optical crystal, in a third direction that is different from the first direction and the second direction. ### Claim 12 (depends on 11) The laser device of claim 11, further comprising: a polarizer device, at the proximal end of the laser device, configured to polarize the first electromagnetic waves before the second optical crystal receives the first electromagnetic waves, wherein the beam splitter is a polarized beam splitter that is configured to reflect the portion of the second electromagnetic waves in the third direction based on a polarity of the second electromagnetic waves. ### Claim 13 A method, comprising: receiving, via a gain device in a first portion of a laser device, an input signal stimulating emission of first electromagnetic waves having a first wavelength; receiving, via an optical crystal in a second portion of the laser device, the first electromagnetic waves, wherein the optical crystal comprises: a first end having a thin film coating disposed thereon, wherein the thin film coating is configured to: emit second electromagnetic waves from the optical crystal based on reception of the first electromagnetic waves, and cause internal reflection of the first electromagnetic waves within the optical crystal, and a second end comprising two angled surfaces that each has a reflective film disposed therein, wherein the two angled surfaces are formed with angles that are symmetric about a logical axis that is parallel to a transmission path in a direction from the first portion of the laser device to the second portion of the laser device; and emitting the second electromagnetic waves via the optical crystal. ### Claim 14 (depends on 13) The method of claim 13, further comprising: receiving an input at a modulator device in the first portion, and modulating, by the modulator device, the first electromagnetic waves before reception of the first electromagnetic waves by the optical crystal. ### Claim 15 (depends on 13) The method of claim 13, further comprising: polarizing the first electromagnetic waves via a polarizer device in the first portion. ### Claim 16 (depends on 13) The method of claim 13, further comprising: reflecting a portion of the second electromagnetic waves, via a beam splitter and after emission from the optical crystal, in a direction that is non-parallel to a transmission path of the first electromagnetic waves. ### Claim 17 (depends on 13) The method of claim 13, wherein the first end of the optical crystal is proximate to the first portion, and wherein the second end of the optical crystal is opposite from the first end of the optical crystal having the thin film coating disposed thereon. ### Claim 18 (depends on 13) The method of claim 13, wherein the reflective film is configured to cause internal reflection of the first electromagnetic waves and internal reflection of the second electromagnetic waves from the second end. ### Claim 19 A method, comprising: emitting electromagnetic waves, toward an object to be inspected, by a laser device that comprises: a first optical crystal, at a first portion of the laser device, configured to emit first electromagnetic waves having a first wavelength; and a second optical crystal, at a second portion of the laser device, configured to receive the first electromagnetic waves and to emit second electromagnetic waves having a second wavelength based on reception of the first electromagnetic waves, wherein the second optical crystal comprises: a first end having a thin film coating disposed thereon, the thin film coating configured to support emission of the second electromagnetic waves from the second optical crystal and to support internal reflection of the first electromagnetic waves in the second optical crystal, and a second end comprising two angled surfaces that each has a reflective film disposed thereon, wherein the two angled surfaces are formed with angles that are symmetric about a logical axis that is parallel to a transmission path in a direction from the first portion of the laser device to the second portion of the laser device; and receiving a portion of the electromagnetic waves after reflection or refraction off of one or more surfaces of the object. ### Claim 20 (depends on 19) The method of claim 19, further comprising: analyzing images of the object based on reception of the electromagnetic waves emitted by the laser device.