# US 10,320,149 B2 · Light-emitting device having III-V semiconductor gain section coupled to whistle-geometry tunable filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,149 B2 - Document ID: US10320149B2 - Status: Granted - Kind: B2 - Application number: 15/741,230 - Filed: 2016-06-29 - Published: 2018-07-05 - Granted: 2019-06-11 - Earliest claimed: 2015-07-01 - Assignees: Stc.Unm - Applicants: Institut Mines-Telecom; University of New Mexico - Inventors: Marek Osinski; Frédéric Grillot - Web page: https://patentgrep.com/patent/US10320149B2 ## CPC - H01S 5/1028: {Coupling to elements in the cavity, e.g. coupling to waveguides adjacent the active region, e.g. forward coupled [DFC] structures} - H01S 5/0225: Out-coupling of light - H01S 5/0612: {controlled by temperature} - H01S 5/068: Stabilisation of laser output parameters (H01S5/0625 takes precedence) - H01S 5/101: {Curved waveguide (H01S5/1243 takes precedence)} - H01S 5/1032: {Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region} - H01S 5/125: Distributed Bragg reflector [DBR] lasers - H01S 5/142: {which comprises an additional resonator} - H01S 5/34313: {with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs} - H01S 5/3434: {with a well layer comprising at least both As and P as V-compounds} - H01S 5/021: {Silicon based substrates} - H01S 5/0215: {Bonding to the substrate} - H01S 5/02325: Mechanically integrated components on mount members or optical micro-benches - H01S 5/0234: Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings - 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 The invention concerns a wavelength tunable semiconductor laser comprising a laser gain section (510) optically coupled to an underlying optical waveguide (520). According to an embodiment of the invention, a first and a second passive microring resonators (530, 560) having a whistle geometry, are arranged on both sides of the laser gain section and evanescently coupled with the optical waveguide (520). Highly reflective broadband mirrors (541, 571) are provided at the free ends of optical waveguide branches (240, 270) tangentially connected to the microring resonators. The first and second passive microrings resonators provide an optical feedback to the laser gain section and allow to select the desired wavelength. The laser structure can be implemented according to a III-V/Si technology. ## Claims ### Claim 1 A wavelength tunable semiconductor laser comprising a laser gain section (510,610,710), the laser gain section being optically coupled to an optical waveguide (520,620,720) having a first end (521,621,721) and a second end (522,622,722), a first passive microring resonator (530,630,730) being arranged between said first end and said laser gain section, characterized in that: the first passive microring resonator is extended by a first optical waveguide branch (540,640,740) tangentially connected thereto according to a whistle geometry, the first optical waveguide branch being provided with a first highly reflective broadband mirror (541,641,741) at its free end, the optical waveguide is provided with a first mirror (523,623,723) at its first end and with a second mirror (524,624,724) at its second end; the first microring resonator is evanescently coupled with the optical waveguide on a first side of the laser gain section to provide an optical feedback to the laser gain section; and an intermediate passive microring resonator (760) arranged between the first passive microring resonator and the optical waveguide, said intermediate passive microring resonator being evanescently coupled with the first passive microring resonator and the optical waveguide. ### Claim 2 (depends on 1) A wavelength tunable semiconductor laser according to claim 1, characterized in that the intermediate passive microring resonator is provided with a controllable heater (790). ### Claim 3 (depends on 1) A wavelength tunable semiconductor laser according to claim 1, characterized in that the first optical waveguide branch is configured as a straight branch. ### Claim 4 (depends on 1) A wavelength tunable semiconductor laser according to claim 1, characterized in that the first highly reflective broadband mirror is a Bragg grating. ### Claim 5 (depends on 1) A wavelength tunable semiconductor laser according to claim 1, characterized in that it further comprises a second passive microring resonator (560) arranged between said second end (522) and said laser gain section, the second passive microring resonator being extended by a second optical waveguide branch (570) tangentially connected thereto according to a whistle geometry, the second waveguide branch being provided with a second highly reflective broadband mirror (571) at its free end, the second passive microring resonator being evanescently coupled with the optical waveguide on a second side, opposite to the first side, of the laser gain section. ### Claim 6 (depends on 5) A wavelength tunable semiconductor laser according to claim 5, characterized in that the first and/or second passive microring resonator(s) is (are) provided with controllable heater(s) (580) and/or (590). ### Claim 7 (depends on 6) A wavelength tunable semiconductor laser according to claim 6, characterized in that the first and/or second passive microring resonator(s) has (have) racetrack geometry. ### Claim 8 (depends on 1) A wavelength tunable semiconductor laser according to claim 1, characterized in that at least one of the said optical waveguide ends is provided with an output mirror redirecting the light out of the waveguide. ### Claim 9 (depends on 1) A wavelength tunable semiconductor laser according to claim 1, characterized in that one of the said optical waveguide ends is provided with an output mirror redirecting the light out of the waveguide, whereas the other optical waveguide end is provided with a highly reflective broadband mirror. ### Claim 10 (depends on 5) A wavelength tunable semiconductor laser according to claim 5, characterized in that at least one of the said optical waveguide ends is provided with an output mirror redirecting the light out of the waveguide. ### Claim 11 (depends on 5) A wavelength tunable semiconductor laser according to claim 5, characterized in that one of the said optical waveguide ends is provided with an output mirror redirecting the light out of the waveguide, whereas the other optical waveguide end is provided with a highly reflective broadband mirror. ### Claim 12 A wavelength tunable semiconductor laser comprising a laser gain section (510,610,710), the laser gain section being optically coupled to an optical waveguide (520,620,720) having a first end (521,621,721) and a second end (522,622,722), a first passive microring resonator (530,630,730) being arranged between said first end and said laser gain section, characterized in that: the first passive microring resonator is extended by a first optical waveguide branch (540,640,740) tangentially connected thereto according to a whistle geometry, the first optical waveguide branch being provided with a first highly reflective broadband mirror (541,641,741) at its free end, the optical waveguide is provided with a first mirror (523,623,723) at its first end and with a second mirror (524,624,724) at its second end; the first microring resonator is evanescently coupled with the optical waveguide on a first side of the laser gain section to provide an optical feedback to the laser gain section; the first and second passive microring resonators, including the first and second optical waveguide branches of said optical waveguide, constitute a pattern of silicon on a SiO2 layer coating a Si substrate; and the wavelength tunable semiconductor laser is implemented according to a III-V/Si technology. ### Claim 13 (depends on 12) A wavelength tunable semiconductor laser according to claim 12, characterized in that the laser gain section comprises a stack of epitaxial III-V layers deposited on a III-V substrate and bonded, epitaxial layers down, onto said pattern of silicon. ### Claim 14 (depends on 13) A wavelength tunable semiconductor laser according to claim 13, characterized in that the III-V epitaxial layers are bonded onto said pattern of silicon by molecular wafer bonding technique. ### Claim 15 (depends on 13) A wavelength tunable semiconductor laser according to claim 13, characterized in that the III-V epitaxial layers are bonded onto said pattern of silicon by adhesive bonding. ### Claim 16 (depends on 14) A wavelength tunable semiconductor laser according to claim 14, characterized in that the laser gain section is coupled to the optical waveguide by an inverted adiabatic silicon taper, the width of the silicon taper increasing from the laser gain section towards either end of the optical waveguide, said inverted adiabatic silicon taper transforming an optical mode of the laser gain section into an optical mode of the optical waveguide. ### Claim 17 (depends on 13) A wavelength tunable semiconductor laser according to claim 13, characterized in that the stack of epitaxial layers comprises a plurality of InGaAsP quantum wells surrounded by two InGaAsP separate confinement heterostructure layers. ### Claim 18 (depends on 13) A wavelength tunable semiconductor laser according to claim 13, characterized in that the stack of epitaxial layers comprises a plurality of InGaAs/AlInGaAs quantum wells surrounded by two AlInGaAs separate confinement heterostructure layers. ### Claim 19 (depends on 15) A wavelength tunable semiconductor laser according to claim 15, characterized in that the laser gain section is coupled to the optical waveguide by an inverted adiabatic silicon taper, the width of the silicon taper increasing from the laser gain section towards either end of the optical waveguide, said inverted adiabatic silicon taper transforming an optical mode of the laser gain section into an optical mode of the optical waveguide. ### Claim 20 A wavelength tunable semiconductor laser comprising a laser gain section (510,610,710), the laser gain section being optically coupled to an optical waveguide (520,620,720) having a first end (521,621,721) and a second end (522,622,722), a first passive microring resonator (530,630,730) being arranged between said first end and said laser gain section, characterized in that: the first passive microring resonator is extended by a first optical waveguide branch (540,640,740) tangentially connected thereto according to a whistle geometry, the first optical waveguide branch being provided with a first highly reflective broadband mirror (541,641,741) at its free end, the optical waveguide is provided with a first mirror (523,623,723) at its first end and with a second mirror (524,624,724) at its second end; the first microring resonator is evanescently coupled with the optical waveguide on a first side of the laser gain section to provide an optical feedback to the laser gain section; the first passive microring resonator is provided with a controllable heater (580,680,780); and an intermediate passive microring resonator (760) arranged between the first passive microring resonator and the optical waveguide, said intermediate passive microring resonator being evanescently coupled with the first passive microring resonator and the optical waveguide.