# US 10,310,188 B2 · Optical connector, optical fiber connection device, optical connector manufacturing method, and optical fiber connection method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,188 B2 - Document ID: US10310188B2 - Status: Granted - Kind: B2 - Application number: 15/777,517 - Filed: 2016-11-17 - Published: 2018-11-15 - Granted: 2019-06-04 - Earliest claimed: 2015-11-19 - Assignees: Fujikura Ltd. - Applicants: Fujikura Ltd. - Inventors: Takaharu Matsuda; Hung Huu Luong - Web page: https://patentgrep.com/patent/US10310188B2 ## CPC - G02B 6/3803: {Adjustment or alignment devices for alignment prior to splicing} - G02B 6/24: Coupling light guides - G02B 6/26: Optical coupling means (G02B6/36, G02B6/42 take precedence) - G02B 6/38: having fibre to fibre mating means - G02B 6/382: {with index-matching medium between light guides (provisionally see G02B6/4212)} - G02B 6/3822: {with beveled fibre ends} - G02B 6/3846: {with fibre stubs} - G02B 6/3858: {Clamping, i.e. with only elastic deformation} - G02B 6/3806: {Semi-permanent connections, i.e. wherein the mechanical means keeping the fibres aligned allow for removal of the fibres (dismountable connectors G02B6/3807)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical connector includes a ferrule, a first optical fiber retained in the ferrule, a clamp section including an insertion section where a second optical fiber is inserted, a solid index-matching material disposed on an end face of the first optical fiber on an insertion section side, and a projecting portion on the end face of the first optical fiber and that projects more toward the insertion section side than a central region of the end face. The clamp section centers and fixes the first optical fiber and the second optical fiber. ## Claims ### Claim 1 An optical connector comprising: a ferrule; a first optical fiber retained in the ferrule; a clamp section including an insertion section where a second optical fiber is inserted; a solid index-matching material disposed on an end face of the first optical fiber on an insertion section side; and a projecting portion on the end face of the first optical fiber and that projects more toward the insertion section side than a central region of the end face, wherein the clamp section centers and fixes the first optical fiber and the second optical fiber, the clamp section further includes a base member including a centering groove, and a lid member that presses the first optical fiber and the second optical fiber toward the centering groove, an end of the first optical fiber is disposed in the centering groove, and the projecting portion is disposed at a lid member side as viewed from the central region. ### Claim 2 (depends on 1) The optical connector according to claim 1, wherein the end face of the first optical fiber is inclined with respect to a plane perpendicular to an optical axis. ### Claim 3 (depends on 2) The optical connector according to claim 2, wherein the end face of the first optical fiber is inclined at an angle of from 4 degrees to 15 degrees, inclusive, with respect to the plane perpendicular to the optical axis. ### Claim 4 (depends on 1) The optical connector according to claim 1, wherein a central region of the solid index-matching material projects out further than a peripheral edge region of the solid index-matching material. ### Claim 5 (depends on 4) The optical connector according to claim 4, wherein the solid index-matching material projects more toward the insertion section side than the projecting portion. ### Claim 6 (depends on 1) The optical connector according to claim 1, wherein an edge of the projecting portion is rounded over. ### Claim 7 (depends on 1) The optical connector according to claim 1, wherein a thickness of the solid index-matching material on an optical axis of the first optical fiber is 20 μm or greater. ### Claim 8 (depends on 7) The optical connector according to claim 7, wherein the thickness and a hardness of the solid index-matching material lies within a range bounded by four points: (thickness: 20 μm, shore hardness E: 30), (thickness: 20 μm, shore hardness E: 85), (thickness: 40 μm, shore hardness E: 85), and (thickness: 60 μm, shore hardness E: 30). ### Claim 9 An optical fiber connection device comprising: a base member including a centering groove that centers an end face of a first optical fiber and an end face of a second optical fiber; a lid member that presses the first optical fiber and the second optical fiber toward the centering groove; an insertion section where the second optical fiber is inserted; a solid index-matching material disposed on an end face of the first optical fiber on the insertion section side; and a projecting portion on the end face of the first optical fiber and that projects more toward the insertion section side than a central region of the end face, wherein an end of the first optical fiber is disposed in the centering groove, and the projecting portion is disposed at a lid member side as viewed from the central region. ### Claim 10 An optical connector manufacturing method comprising: providing an unassembled optical connector that includes a ferrule, a first optical fiber retained in the ferrule, and a clamp section including an insertion section, a base member, and a lid member; inserting a second optical fiber into the clamp section through the insertion section; abutting an end face of the first optical fiber, disposed in a centering groove of the base member, and an end face of the second optical fiber against each other; and fixing the first optical fiber and the second optical fiber using the clamp section, by pressing the first optical fiber and the second optical fiber toward the centering groove with the lid member, after the first optical fiber and the second optical fiber have been abutted against each other, wherein a solid index-matching material is disposed on an end face of the first optical fiber on an insertion section side, a projecting portion on the end face of the first optical fiber projects more toward the insertion section side than a central region of the end face, and the projecting portion is disposed at a lid member side as viewed from the central region. ### Claim 11 An optical fiber connection method comprising: abutting an end face of a first optical fiber, disposed in a centering groove of a base member of a clamp section including the base member and a lid member, and an end face of a second optical fiber against each other, wherein the second optical fiber is inserted into the clamp section through an insertion section of the clamp section; and fixing the first optical fiber and the second optical fiber using the clamp section, by pressing the first optical fiber and the second optical fiber toward the centering groove with the lid member, after the first optical fiber and the second optical fiber have been abutted against each other, wherein a solid index-matching material is disposed on an end face of the first optical fiber on an insertion section side, a projecting portion formed on the end face of the first optical fiber projects more toward the insertion section side than a central region of the end face, and the projecting portion is disposed at a lid member side as viewed from the central region.