# US 12,007,530 B2 · Photonic crystal optical resonator and method for fabricating same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,530 B2 - Document ID: US12007530B2 - Status: Granted - Kind: B2 - Application number: 17/430,375 - Filed: 2020-01-31 - Published: 2022-03-03 - Granted: 2024-06-11 - Earliest claimed: 2019-02-14 - Assignees: Nippon Telegraph and Telephone Corporation - Applicants: Nippon Telegraph and Telephone Corporation - Inventors: Kenta Takata; Masaya Notomi; Akihiko Shinya; Eiichi Kuramochi; Hideaki Taniyama; Shota Kita - Web page: https://patentgrep.com/patent/US12007530B2 ## CPC - G02B 1/005: {made of photonic crystals or photonic band gap materials (photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295)} - G02B 6/1225: {comprising photonic band-gap structures or photonic lattices} - B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals - H01S 5/10: Construction or shape of the optical resonator {, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region (H01S5/20 takes precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - 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 Each of six first lattice elements adjacent to a light confinement portion shifts from a lattice point in a direction of separating from the light confinement portion, and each of twelve second lattice elements shifts from a lattice point in a direction of separating from the light confinement portion. The second lattice elements are lattice elements arranged to be adjacent to the first lattice elements on a side of separating from the light confinement portion. Moreover, each of the first lattice elements has a smaller diameter than other lattice elements arranged on lattice points. ## Claims ### Claim 1 A photonic crystal optical resonator comprising: a photonic crystal main body including a base part and a plurality of columnar lattice elements each having a different refractive index from that of the base part, the plurality of columnar lattice elements being provided on the base part spaced apart in a triangular lattice at intervals not more than a wavelength of targeted light; and a light confinement portion comprising a point defect configured by a portion obtained by removing at least one of the plurality of columnar lattice elements on respective lattice points of the photonic crystal main body; wherein each of six first lattice elements of the plurality of columnar lattice elements adjacent to the light confinement portion is configured to shift from first lattice points in a direction of separating from the light confinement portion; wherein each of twelve second lattice elements of the plurality of columnar lattice elements adjacent to the six first lattice elements on a side of separating from the light confinement portion is configured to shift from second lattice points in the direction of separating from the light confinement portion; wherein each of the six first lattice elements has a smaller diameter than others of the plurality of columnar lattice elements; wherein optimization of an amount of shift of the six first lattice elements, optimization of an amount of shift of the twelve second lattice elements, and optimization of a diameter of the six first lattice elements such that a Q value of the photonic crystal optical resonator is maximized simultaneously; and wherein the Q value of the photonic crystal optical resonator that is maximized exceeds 10 million. ### Claim 2 (depends on 1) The photonic crystal optical resonator according to claim 1, wherein the amount of the shift and the diameter of the six first lattice elements are optimized to meet a difference in refractive index between the base part and the plurality of columnar lattice elements such that the Q value of the photonic crystal optical resonator is maximized. ### Claim 3 (depends on 1) The photonic crystal optical resonator according to claim 1, wherein each of the plurality of columnar lattice elements has a circular columnar shape. ### Claim 4 (depends on 3) The photonic crystal optical resonator according to claim 3, wherein: a radius of third lattice elements of the plurality of columnar lattice elements is set to be any value within a range from 0.3 times to 0.325 times a distance between adjacent ones of the plurality of columnar lattice elements; and a radius of the six first lattice elements is set to be any value within a range from 0.225 times to 0.255 times the distance between the adjacent ones of the plurality of columnar lattice elements. ### Claim 5 (depends on 4) The photonic crystal optical resonator according to claim 4, wherein: the amount of the shift of the six first lattice elements is set to be any value within a range from 0.165 times to 0.25 times the distance between the adjacent ones of the plurality of columnar lattice elements; and the amount of the shift of the twelve second lattice elements is set to be any value within a range from 0.038 times to 0.054 times the distance between the adjacent ones of the plurality of columnar lattice elements. ### Claim 6 A method of producing a photonic crystal optical resonator, the method comprising: providing a photonic crystal main body including a base part and a plurality of columnar lattice elements each having a different refractive index from that of the base part, the plurality of columnar lattice elements being provided on the base part spaced apart in a triangular lattice at intervals not more than a wavelength of targeted light; providing a light confinement portion comprising a point defect configured by a portion obtained by removing at least one of the plurality of columnar lattice elements on respective lattice points of the photonic crystal main body; shifting each of six first lattice elements adjacent to the light confinement portion from first lattice points in a direction of separating from the light confinement portion, wherein each of the six first lattice elements has a smaller diameter than others of the plurality of columnar lattice elements; shifting each of twelve second lattice elements adjacent to the six first lattice elements on a side of separating from the light confinement portion from second lattice points in the direction of separating from the light confinement portion; and simultaneously performing optimization of an amount of shift of the six first lattice elements, optimization of an amount of shift of the twelve second lattice elements, and optimization of a diameter of the six first lattice elements such that a Q value of the photonic crystal optical resonator is maximized, wherein the Q value of the photonic crystal optical resonator that is maximized exceeds 10 million. ### Claim 7 (depends on 6) The method according to claim 6, wherein each of the plurality of columnar lattice elements has a circular columnar shape. ### Claim 8 (depends on 7) The method according to claim 7, wherein: a radius of third lattice elements of the plurality of columnar lattice elements is set to be any value within a range from 0.3 times to 0.325 times a distance between adjacent ones of the plurality of columnar lattice elements; and a radius of the six first lattice elements is set to be any value within a range from 0.225 times to 0.255 times the distance between the adjacent ones of the plurality of columnar lattice elements. ### Claim 9 (depends on 8) The method according to claim 8, wherein: the amount of the shift of the six first lattice elements is set to be any value within a range from 0.165 times to 0.25 times the distance between the adjacent ones of the plurality of columnar lattice elements; and the amount of the shift of the twelve second lattice elements is set to be any value within a range from 0.038 times to 0.054 times the distance between the adjacent ones of the plurality of columnar lattice elements.