# US 2021/0344166 A1 · Thermally-controlled photonic structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344166 A1 - Document ID: US20210344166A1 - Status: Published application - Kind: A1 - Application number: 17/032,787 - Filed: 2020-09-25 - Published: 2021-11-04 - Earliest claimed: 2020-04-29 - Assignees: Lumentum Operations LLC - Applicants: Lumentum Operations LLC - Inventors: Shibnath PATHAK; Duanhua KONG; Michael C. LARSON; Amit MIZRAHI - Web page: https://patentgrep.com/patent/US20210344166A1 ## CPC - H01S 5/02453: {Heating, e.g. the laser is heated for stabilisation against temperature fluctuations of the environment (H01S5/0612 takes precedence, for monolithically integrated heaters see also H01S5/0261)} - H01S 5/0612: {controlled by temperature} - H01S 5/068: Stabilisation of laser output parameters (H01S5/0625 takes precedence) - H01S 5/22: having a ridge or stripe structure - H01S 5/02315: Support members, e.g. bases or carriers - H01S 5/02461: {Structure or details of the laser chip to manipulate the heat flow, e.g. passive layers in the chip with a low heat conductivity} - 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 In some implementations, a thermally-controlled photonic structure may include a suspended region that is suspended over a substrate; a plurality of bridge elements connected to the suspended region and configured to suspend the suspended region over the substrate, where a plurality of openings are defined between the plurality of bridge elements; and at least one heater element having a modulated width disposed on the suspended region. The at least one heater element having the modulated width may include at least one section of a greater width and at least one section of a lesser width. The at least one section of the greater width may be in alignment with an opening of the plurality of openings and the at least one section of the lesser width may be in alignment with a bridge element of the plurality of bridge elements. ## Claims ### Claim 1 A thermally-controlled mirror structure, comprising: an optical waveguide region suspended over a substrate, wherein the optical waveguide region includes a grating for reflecting light; a plurality of bridge elements connected to the optical waveguide region and configured to suspend the optical waveguide region over the substrate, wherein a plurality of openings are defined between the plurality of bridge elements; and at least one heater element having a modulated width disposed on the optical waveguide region, wherein the at least one heater element having the modulated width includes at least one section of a greater width and at least one section of a lesser width, and wherein the at least one section of the greater width is in alignment with an opening of the plurality of openings and the at least one section of the lesser width is in alignment with a bridge element of the plurality of bridge elements. ### Claim 2 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein the at least one heater element having the modulated width comprises a resistive heater. ### Claim 3 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein the at least one heater element having the modulated width has one unmodulated side and one modulated side. ### Claim 4 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein the at least one heater element having the modulated width has two modulated sides. ### Claim 5 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein the at least one heater element having the modulated width is positioned above a waveguide ridge of the optical waveguide region. ### Claim 6 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein the at least one heater element having the modulated width is positioned at a side of a waveguide ridge of the optical waveguide region. ### Claim 7 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein the at least one heater element having the modulated width comprises a first heater element and a second heater element, and at least one of the first heater element and the second heater element has the modulated width, and wherein the first heater element and the second heater element are positioned at opposite sides of a waveguide ridge of the optical waveguide region. ### Claim 8 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein lengths of the plurality of bridge elements decrease in a direction of light propagation of the optical waveguide region, and wherein the at least one section of the greater width includes a plurality of sections of the greater width that increase in width in the direction of light propagation. ### Claim 9 (depends on 1) The thermally-controlled mirror structure of claim 1, wherein a first set of bridge elements, of the plurality of bridge elements, at a first side of the optical waveguide region are offset from a second set of bridge elements, of the plurality of bridge elements, at a second side of the optical waveguide region. ### Claim 10 A thermally-controlled photonic structure, comprising: a suspended region that is suspended over a substrate; a plurality of bridge elements connected to the suspended region and configured to suspend the suspended region over the substrate, wherein a plurality of openings are defined between the plurality of bridge elements; and at least one heater element having a modulated width disposed on the suspended region, wherein the at least one heater element having the modulated width includes at least one section of a greater width and at least one section of a lesser width, and wherein the at least one section of the greater width is in alignment with an opening of the plurality of openings and the at least one section of the lesser width is in alignment with a bridge element of the plurality of bridge elements. ### Claim 11 (depends on 10) The thermally-controlled photonic structure of claim 10, wherein the at least one heater element having the modulated width has rectangular modulation. ### Claim 12 (depends on 10) The thermally-controlled photonic structure of claim 10, wherein the at least one heater element having the modulated width has triangular modulation. ### Claim 13 (depends on 10) The thermally-controlled photonic structure of claim 10, wherein the at least one heater element having the modulated width has sinusoidal modulation. ### Claim 14 (depends on 10) The thermally-controlled photonic structure of claim 10, wherein an opening, of the plurality of openings, at an edge section of the thermally-controlled photonic structure, is sized differently than an opening, of the plurality of openings, at a middle section of the thermally-controlled photonic structure, and wherein the at least one section of the lesser width includes a first section of the lesser width at the edge section and a second section of the lesser width at the middle section, and the first section of the lesser width is sized differently than the second section of the lesser width. ### Claim 15 (depends on 10) The thermally-controlled photonic structure of claim 10, wherein lengths of the plurality of bridge elements decrease in a direction of light propagation of the thermally-controlled photonic structure, and wherein the at least one section of the greater width includes a plurality of sections of the greater width that increase in width in the direction of light propagation. ### Claim 16 (depends on 10) The thermally-controlled photonic structure of claim 10, wherein a first set of bridge elements, of the plurality of bridge elements, at a first side of the suspended region are offset from a second set of bridge elements, of the plurality of bridge elements, at a second side of the suspended region. ### Claim 17 A tunable laser, comprising: a thermally-controlled mirror structure, comprising: an optical waveguide region suspended over a substrate, wherein the optical waveguide region includes a grating for reflecting light; a plurality of bridge elements connected to the optical waveguide region and configured to suspend the optical waveguide region over the substrate, wherein a plurality of openings are defined between the plurality of bridge elements; and at least one heater element having a modulated width disposed on the optical waveguide region, wherein the at least one heater element having the modulated width includes at least one section of a greater width and at least one section of a lesser width, and wherein the at least one section of the greater width is in alignment with an opening of the plurality of openings and the at least one section of the lesser width is in alignment with a bridge element of the plurality of bridge elements. ### Claim 18 (depends on 17) The tunable laser of claim 17, wherein the at least one heater element having the modulated width comprises a first heater element and a second heater element, and at least one of the first heater element and the second heater element has the modulated width, and wherein the first heater element and the second heater element are positioned at opposite sides of a waveguide ridge of the optical waveguide region. ### Claim 19 (depends on 17) The tunable laser of claim 17, wherein lengths of the plurality of bridge elements decrease in a direction of light propagation of the optical waveguide region, and wherein the at least one section of the greater width includes a plurality of sections of the greater width that increase in width in the direction of light propagation. ### Claim 20 (depends on 17) The tunable laser of claim 17, wherein an opening, of the plurality of openings, at an edge section of the thermally-controlled mirror structure, is sized differently than an opening, of the plurality of openings, at a middle section of the thermally-controlled mirror structure, and wherein the at least one section of the lesser width includes a first section of the lesser width at the edge section and a second section of the lesser width at the middle section, and the first section of the lesser width is sized differently than the second section of the lesser width.