# US 12,687,676 B2 · Optical chip and optical communication apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,687,676 B2 - Document ID: US12687676B2 - Status: Granted - Kind: B2 - Application number: 18/227,776 - Filed: 2023-07-28 - Published: 2024-03-07 - Granted: 2026-07-21 - Earliest claimed: 2022-09-02 - Assignees: Fujitsu Optical Components Limited - Applicants: Fujitsu Optical Components Limited - Inventors: Masaki Sugiyama - Web page: https://patentgrep.com/patent/US12687676B2 ## CPC - G01M 11/33: {with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face} - G02B 6/125: Bends, branchings or intersections - G01M 11/30: {Testing of optical devices, constituted by fibre optics or optical waveguides} - G02B 2006/12147: {Coupler} - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical chip includes a chip area located on a wafer, and an optical circuit arranged in the chip area. The optical chip includes a first waveguide that is connected to a first operational fiber, a second waveguide, and a first coupler that includes a first port that is connected to the first waveguide and the second waveguide and a second port that is connected to the optical circuit. Furthermore, the optical chip includes a first trench that is formed on a surface of the chip area, that is connected to the second waveguide, and in which a first test purpose fiber is inserted. ## Claims ### Claim 1 An optical chip including a chip area located on a wafer and an optical circuit arranged in the chip area, the optical chip comprising: a first waveguide that is connected to a first operational fiber; a second waveguide; a first coupler that includes a first port that is connected to the first waveguide and that is connected to the second waveguide, and a second port that is connected to the optical circuit; a first trench that is formed on a surface of the chip area and that is connected to the second waveguide; a third waveguide that is connected to a second operational fiber; a fourth waveguide; a second coupler that includes a third port that is connected to the third waveguide and that is connected to the fourth waveguide, and a fourth port that is connected to the optical circuit; and a second trench that is formed on the surface of the chip area and that is connected to the fourth waveguide; and wherein the first trench in which a first test purpose fiber is inserted is connected to the second waveguide, and the second trench in which a second test purpose fiber is inserted is connected to the fourth waveguide. ### Claim 2 (depends on 1) The optical chip according to claim 1, wherein the optical chip includes at least one of waveguides of the second waveguide that is arranged such that the second waveguide is not orthogonal to a side surface among side surfaces of the first trench and that is connected to the second waveguide, and the fourth waveguide that is arranged such that the fourth waveguide is not orthogonal to a side surface that is included in the side surfaces of the second trench and that is connected to the fourth waveguide. ### Claim 3 (depends on 2) The optical chip according to claim 2, wherein the optical chip includes at least one of trenches of the first trench that is arranged such that the side surface of the first trench connected to the second waveguide is arranged at a position inclined with respect to a side of the chip area, and the second trench that is arranged such that the side surface of the second trench connected to the fourth waveguide is arranged at a position inclined with respect to a side of the chip area. ### Claim 4 (depends on 1) The optical chip according to claim 1, further including: a first edge coupler that is connected to at least one of the second waveguide and the first test purpose fiber that is inserted inside of the first trench; and a second edge coupler that is connected to at least one of the fourth waveguide and the second test purpose fiber that is inserted inside of the second trench. ### Claim 5 (depends on 1) The optical chip according to claim 1, wherein the first port is among a plurality of first ports, the second port is among a plurality of second ports, the third port is among a plurality of third ports, and the fourth port is among a plurality of fourth ports, and the optical chip includes at least one coupler among couplers of the first coupler that is a 2×2 coupler in which a number of the plurality of first ports is two and a number of the plurality of second ports is two, and the second coupler that is a 2×2 coupler in which a number of the plurality of third ports is two and a number of the plurality of fourth ports is two. ### Claim 6 (depends on 1) The optical chip according to claim 1, wherein the first port is among a plurality of first ports, the second port is among a plurality of second ports, the third port is among a plurality of third ports, and the fourth port is among a plurality of fourth ports, and the optical chip includes at least one coupler among couplers of the first coupler that is a variable attenuator having a Mach-Zehnder structure in which a number of the plurality of first ports is two and a number of the plurality of second ports is one, and the second coupler that is a variable attenuator having a Mach-Zehnder structure in which a number of the plurality of third ports is two and a number of the plurality of fourth ports is one. ### Claim 7 An optical communication apparatus comprising: an optical chip that includes a chip area located on a wafer and an optical circuit arranged in the chip area, wherein the optical circuit includes a first modulator, a second modulator, a first receiver, and a second receiver, and the chip area includes a first waveguide that is connected to a first operational fiber that is used for local emission light, a second waveguide, a first coupler that includes a first port that is connected to the first waveguide and that is connected to the second waveguide, and a second port that is connected to the optical circuit, a first trench that is formed on a surface of the chip area and that is connected to the second waveguide, a third waveguide that is connected to a second operational fiber that is used for reception light, a fourth waveguide, a second coupler that includes a third port that is connected to the third waveguide and that is connected to the fourth waveguide, and a fourth port that is connected to the first receiver, a second trench that is formed on the surface of the chip area and that is connected to the fourth waveguide, a fifth waveguide, a third coupler that includes a fifth port that is connected to the third waveguide and that is connected to the fifth waveguide, and a sixth port that is connected to the second receiver, a third trench that is formed on the surface of the chip area and that is connected to the fifth waveguide, a sixth waveguide that is connected to a third operational fiber that is used for transmission light, a seventh waveguide, a fourth coupler that includes a seventh port that is connected to the sixth waveguide and that is connected to the seventh waveguide, and an eighth port that is connected to the first modulator, a fourth trench that is formed on the surface of the chip area and that is connected to the seventh waveguide, an eighth waveguide, a fifth coupler that includes a ninth port that is connected to the sixth waveguide and that is connected to the eighth waveguide, and a tenth port that is connected to the second modulator, and a fifth trench that is formed on the surface of the chip area and that is connected to the eighth waveguide. ### Claim 8 (depends on 7) The optical communication apparatus according to claim 7, wherein the first trench in which a first test purpose fiber is inserted is connected to the second waveguide, the second trench in which a second test purpose fiber is inserted is connected to the fourth waveguide, the third trench in which a third test purpose fiber is inserted is connected to the fifth waveguide, the fourth trench in which a fourth test purpose fiber is inserted is connected to the seventh waveguide, and the fifth trench in which a fifth test purpose fiber is inserted is connected to the eighth waveguide. ### Claim 9 (depends on 7) The optical communication apparatus according to claim 7, wherein the first trench, the second trench, the third trench, the fourth trench, and the fifth trench are arranged on substantially a same line in the chip area. ### Claim 10 (depends on 7) The optical communication apparatus according to claim 7, wherein the second waveguide, the fourth waveguide, the fifth waveguide, the seventh waveguide, and the eighth waveguide are arranged at a same interval pitch in a same direction. ### Claim 11 An optical receiver comprising an optical chip that includes a chip area located on a wafer and an optical circuit arranged in the chip area, wherein the optical circuit includes a first receiver, and a second receiver, and the chip area includes a first waveguide that is connected to a first operational fiber that is used for local emission light, a second waveguide, a first coupler that includes a first port that is connected to the first waveguide and that is connected to the second waveguide, and a second port that is connected to the optical circuit, a first trench that is formed on a surface of the chip area and that is connected to the second waveguide, a third waveguide that is connected to a second operational fiber that is used for reception light, a fourth waveguide, a second coupler that includes a third port that is connected to the third waveguide and that is connected to the fourth waveguide, and a fourth port that is connected to the first receiver, a second trench that is formed on the surface of the chip area and that is connected to the fourth waveguide, a fifth waveguide, a third coupler that includes a fifth port that is connected to the third waveguide and that is connected to the fifth waveguide, and a sixth port that is connected to the second receiver, and a third trench that is formed on the surface of the chip area and that is connected to the fifth waveguide. ### Claim 12 (depends on 11) The optical receiver according to claim 11, wherein the first trench in which a first test purpose fiber is inserted is connected to the second waveguide, the second trench in which a second test purpose fiber is inserted is connected to the fourth waveguide, and the third trench in which a third test purpose fiber is inserted is connected to the fifth waveguide. ### Claim 13 An optical transmitter comprising an optical chip that includes a chip area located on a wafer, and an optical circuit arranged in the chip area, wherein the optical circuit includes a first modulator, and a second modulator, and the chip area includes a first waveguide that is connected to a first operational fiber that is used for local emission light, a second waveguide, a first coupler that includes a first port that is connected to the first waveguide and that is connected to the second waveguide, and a second port that is connected to the optical circuit, a first trench that is formed on a surface of the chip area and that is connected to the second waveguide, a third waveguide that is connected to a second operational fiber that is used for transmission light, a fourth waveguide, a second coupler that includes a third port that is connected to the third waveguide and that is connected to the fourth waveguide, and a fourth port that is connected to the first modulator, a second trench that is formed on the surface of the chip area and that is connected to the fourth waveguide, a fifth waveguide, a third coupler that includes a fifth port that is connected to the third waveguide and that is connected to the fifth waveguide, and a sixth port that is connected to the second modulator, and a third trench that is formed on the surface of the chip area and that is connected to the fifth waveguide. ### Claim 14 (depends on 13) The optical transmitter according to claim 13, wherein the first trench in which a first test purpose fiber is inserted is connected to the second waveguide, the second trench in which a second test purpose fiber is inserted is connected to the fourth waveguide, and the third trench in which a third test purpose fiber is inserted is connected to the fifth waveguide.