# US 2018/0323579 A1 · Semiconductor laser device, chip on submount, and semiconductor laser module > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323579 A1 - Document ID: US20180323579A1 - Status: Published application - Kind: A1 - Application number: 16/027,938 - Filed: 2018-07-05 - Published: 2018-11-08 - Earliest claimed: 2016-01-13 - Assignees: Furukawa Electric Co., Ltd. - Applicants: Furukawa Electric Co., Ltd. - Inventors: Eisaku KAJI; Yutaka OHKI - Web page: https://patentgrep.com/patent/US20180323579A1 ## CPC - H01S 5/1014: {Tapered waveguide, e.g. spotsize converter (H01S5/1064 takes precedence)} - G02B 6/29362: {Serial cascade of filters or filtering operations, e.g. for a large number of channels} - G02B 6/2938: {for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM} - G02B 6/32: having lens focusing means {positioned between opposed fibre ends (with lens being an integral part of the single fibre end G02B6/262)} - G02B 6/34: utilising prism or grating {(G02B6/293 takes precedence)} - G02B 6/4206: {Optical features (G02B6/4207, G02B6/421 take precedence)} - G02B 6/4215: {the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence)} - H01S 5/023: Mount members, e.g. sub-mount members - H01S 5/0233: Mounting configuration of laser chips - H01S 5/0235: Method for mounting laser chips - H01S 5/0421: {characterised by the semiconducting contacting layers (electrodes H01S5/0425)} - H01S 5/04254: {characterised by the shape} - H01S 5/1003: {Waveguide having a modified shape along the axis, e.g. branched, curved, tapered, voids} - H01S 5/1039: {Details on the cavity length} - H01S 5/22: having a ridge or stripe structure - H01S 5/4012: {Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms} - H01S 5/0071: {for beam steering, e.g. using a mirror outside the cavity to change the beam direction} - H01S 5/0202: {Cleaving} - H01S 5/02216: Butterfly-type, i.e. with electrode pins extending horizontally from the housings - H01S 5/02251: using optical fibres - H01S 5/02326: Arrangements for relative positioning of laser diodes and optical components, e.g. grooves in the mount to fix optical fibres or lenses - H01S 5/04256: {characterised by the configuration} - H01S 5/3432: {the whole junction comprising only (AI)GaAs} - H01S 2301/166: Single transverse or lateral mode - H01S 2301/176: Specific passivation layers on surfaces other than the emission facet - 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 - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A semiconductor laser device of an edge emission type, where a waveguide mode is multi-mode, is provided. The semiconductor laser device includes a first facet of the waveguide on an emission direction front side, the first facet having a first width in a horizontal direction perpendicular to a longitudinal direction of the waveguide; and a second facet of the waveguide on an emission direction rear side, the second facet having the first width, wherein a width of the waveguide, in the horizontal direction, is at least partially narrower than the first width, between the first facet and the second facet. ## Claims ### Claim 1 A semiconductor laser device of an edge emission type, where a waveguide mode is multi-mode, the semiconductor laser device comprising: a first facet of the waveguide on an emission direction front side, the first facet having a first width in a horizontal direction perpendicular to a longitudinal direction of the waveguide; and a second facet of the waveguide on an emission direction rear side, the second facet having the first width, wherein a width of the waveguide, in the horizontal direction, is at least partially narrower than the first width, between the first facet and the second facet. ### Claim 2 (depends on 1) The semiconductor laser device according to claim 1, wherein a ratio of length of a range having the first width, on the emission direction front side, relative to total length from the first facet on the emission direction front side to the second facet on the emission direction rear side is 20% or more and 56% or less. ### Claim 3 (depends on 1) The semiconductor laser device according to claim 1, wherein a narrowest width of the waveguide between the first facet on the emission direction front side and the second facet on the emission direction rear side is 30 μm or more and 75 μm or less. ### Claim 4 (depends on 1) The semiconductor laser device according to claim 1, further comprising a current injection region from which current is injected into the waveguide, the current injection region having a width, in the horizontal direction, that is at least partially narrower, between the first facet on the emission direction front side and the second facet on the emission direction rear side, than a width, in the horizontal direction, of the current injection region on the emission direction front side. ### Claim 5 (depends on 4) The semiconductor laser device according to claim 4, further comprising a current non-injection region where the current injection region is not formed, the current non-rejection region being provided on the emission direction front side or the emission direction rear side. ### Claim 6 A semiconductor laser device of an edge emission type, where a waveguide mode is multi-mode, the semiconductor laser device comprising: a first facet of the waveguide on an emission direction front side, the first facet having a first width in a horizontal direction perpendicular to a longitudinal direction of the waveguide; and a second facet of the waveguide on an emission direction rear side, the second facet having the first width; and a current injection region from which current is injected into the waveguide, the current injection region having a width, in the horizontal direction, that is at least partially narrower, between the first facet on an emission direction front side and the second facet on an emission direction rear side, than a width, in the horizontal direction, of another region of the current injection region. ### Claim 7 (depends on 6) The semiconductor laser device according to claim 6, further comprising a current non-injection region where the current injection region is not formed, the current non-rejection region being provided on the emission direction front side or the emission direction rear side. ### Claim 8 A semiconductor laser device of an edge emission type, where a waveguide mode is multi-mode, the semiconductor laser device comprising; a current injection region from which current is injected into the waveguide, the current injection region having a width narrower than the waveguide in a horizontal direction perpendicular to a longitudinal direction of the waveguide; and a coverage region having a coverage width obtained by dividing, by two, a result of subtracting the width of the current injection region from a width of the waveguide in the horizontal direction, the coverage width being at least partially wider than 5 μm and 23 μm or less, between a first facet of the waveguide on an emission direction front side and a second facet of the waveguide on an emission direction rear side. ### Claim 9 (depends on 7) The semiconductor laser device according to claim 7, wherein the coverage width is 15 μm or less. ### Claim 10 (depends on 7) The semiconductor laser device according to claim 7, wherein the coverage width is 15.3% or less of the width of the waveguide. ### Claim 11 (depends on 7) The semiconductor laser device according to claim 7, wherein the coverage width is 10% or less of the width of the waveguide. ### Claim 12 (depends on 1) A chip on submount comprising: the semiconductor laser device according to claim 1; and a mount being electrically conductive, wherein the semiconductor laser device is placed on the mount. ### Claim 13 (depends on 6) A chip on submount comprising: the semiconductor laser device according to claim 6; and a mount being electrically conductive, wherein the semiconductor laser device is placed on the mount. ### Claim 14 (depends on 8) A chip on submount comprising: the semiconductor laser device according to claim 8; and a mount being electrically conductive, wherein the semiconductor laser device is placed on the mount. ### Claim 15 (depends on 12) A semiconductor laser module comprising: the chip on submount according to claim 12; and at least one lens provided in an optical path between the semiconductor laser device and an optical fiber, thereby to couple the laser light radiated by the semiconductor laser device into the optical fiber. ### Claim 16 (depends on 13) A semiconductor laser module comprising: the chip on submount according to claim 13; and at least one lens provided in an optical path between the semiconductor laser device and an optical fiber, thereby to couple the laser light radiated by the semiconductor laser device into the optical fiber. ### Claim 17 (depends on 14) A semiconductor laser module comprising: the chip on submount according to claim 14; and at least one lens provided in an optical path between the semiconductor laser device and an optical fiber, thereby to couple the laser light radiated by the semiconductor laser device into the optical fiber. ### Claim 18 (depends on 15) The semiconductor laser module according to claim 15, further comprising a diffraction grating fixing an emission wavelength of the semiconductor laser device, at an intermediate portion of the optical path from the semiconductor laser device to the optical fiber. ### Claim 19 (depends on 16) The semiconductor laser module according to claim 16, further comprising a diffraction grating fixing an emission wavelength of the semiconductor laser device, at an intermediate portion of an optical path from the semiconductor laser device to the optical fiber. ### Claim 20 (depends on 17) The semiconductor laser module according to claim 17, further comprising a diffraction grating fixing an emission wavelength of the semiconductor laser device, at an intermediate portion of an optical path from the semiconductor laser device to the optical fiber.