# US 8,787,716 B2 · Fibre coupler > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,716 B2 - Document ID: US8787716B2 - Status: Granted - Kind: B2 - Application number: 12/989,648 - Filed: 2009-04-09 - Published: 2011-05-26 - Granted: 2014-07-22 - Earliest claimed: 2008-04-25 - Assignees: Trumpf Laser GmbH; JENOPTIK Laser GmbH - Applicants: Malte Kumkar; Marcin Michal Kozak; Clemens Hoenninger; Andreas Liem; Thomas Gabler; Inka Manek-Hoenninger - Inventors: Malte Kumkar; Marcin Michal Kozak; Clemens Hoenninger; Andreas Liem; Thomas Gabler; Inka Manek-Hoenninger - Web page: https://patentgrep.com/patent/US8787716B2 ## CPC - G02B 6/2856: {formed or shaped by thermal heating means, e.g. splitting, branching and/or combining elements} - H01S 3/094007: {Cladding pumping, i.e. pump light propagating in a clad surrounding the active core} - H01S 3/094019: {Side pumped fibre, whereby pump light is coupled laterally into the fibre via an optical component like a prism, or a grating, or via V-groove coupling} - H01S 3/094053: {Fibre coupled pump, e.g. delivering pump light using a fibre or a fibre bundle} - Y10T 29/49826: Assembling or joining - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A fiber coupler with an inner tube, an inner fiber arranged within the inner tube and several outer fibers arranged around the inner fiber, is disclosed, wherein said fiber coupler tapers in the longitudinal direction of the inner fiber from a main section to a terminal section and the inner cross section on the inner tube corresponds to the diameter of the inner fiber along the tapering section of the fiber coupler. ## Claims ### Claim 1 A fiber coupler, comprising: an inner tube; an inner fiber disposed in the inner tube; multiple outer fibers disposed around the inner fiber, and a main section; a terminal section; and a tapering section defined between the main section and the terminal section, wherein the fiber coupler tapers in the longitudinal direction of the inner fiber along the tapering section and the internal cross-section of the inner tube along the tapering section corresponds to the cross-section of the inner fiber, wherein the outer fibers are in optical contact with the inner fiber via the inner tube along the entire tapering section. ### Claim 2 (depends on 1) The fiber coupler according to claim 1, wherein the internal cross-section of the inner tube remains equal along the tapering section. ### Claim 3 (depends on 1) The fiber coupler according to claim 1, wherein the inner tube is collapsed on the inner fiber along the tapering section. ### Claim 4 (depends on 1) The fiber coupler according to claim 1, wherein the inner tube is in direct optical contact with the inner fiber along the entire tapering section. ### Claim 5 (depends on 1) The fiber coupler according to claim 1, wherein the outer fibers extend along the entire tapering section and their cross-sectional area decreases accordingly. ### Claim 6 (depends on 1) The fiber coupler according to claim 1, wherein the inner tube defines a wall thickness, and wherein the outer fibers extend up to the inner tube, are optically coupled to a front side of the inner tube, and the wall thickness of the inner tube decreases along the tapering section. ### Claim 7 (depends on 1) The fiber coupler according to claim 1, further comprising an outer tube in which the inner tube is at least partially situated and in which the outer fibers at least partially extend. ### Claim 8 (depends on 7) The fiber coupler according to claim 7, wherein the outer fibers extend between the outer tube and the inner tube. ### Claim 9 (depends on 7) The fiber coupler according to claim 7, wherein the outer tube defines an outer tube thickness and the wall thickness of the outer tube decreases along the tapering section. ### Claim 10 (depends on 7) The fiber coupler according to claim 7, wherein the outer tube extends along the entire tapering section. ### Claim 11 A method for producing a fiber coupler, comprising: creating a blank, comprising providing multiple outer fibers and an inner tube defining an internal cross-section, the multiple outer fibers are situated around the inner tube, a portion of the blank being tapered along a longitudinal direction of the inner tube to define a tapered section having a longitudinal length, the tapered section connecting a main section of the blank to a terminal section of the blank, and forming the tapered section; inserting an inner fiber into the inner tube, wherein after the tapering step, an internal cross-section of the inner tube along the tapered section corresponds to the cross-section of the inserted inner fiber; and collapsing the inner tube on the inner fiber along the entire longitudinal length of the tapered section. ### Claim 12 (depends on 11) The method according to claim 11, wherein the internal cross-section of the inner tube remains unchanged during the tapering step. ### Claim 13 (depends on 11) The method according to claim 11, further comprising pressing the outer fibers against a front side of the inner tube. ### Claim 14 (depends on 13) The method according to claim 13, wherein step of inserting an inner fiber into the inner tube is executed before the tapering step and the collapsing of the inner tube is executed simultaneously with and spatially trailing the tapering step. ### Claim 15 (depends on 11) The method according to claim 11, wherein the outer fibers are inserted between the inner tube and an outer tube, which at least partially encloses the blank in the longitudinal direction. ### Claim 16 (depends on 15) The method according to claim 15, wherein the outer tube includes a closed internal cross-section to receive the inner fiber in the area of the tapered section to be created in the tapering step. ### Claim 17 (depends on 11) The method according to claim 11, wherein the wall thickness of the inner tube is decreased along the tapered section in the tapering step. ### Claim 18 (depends on 11) The method according to claim 11, wherein the tapering of the blank in the tapering step is caused by material deformation. ### Claim 19 (depends on 11) The method according to claim 11, wherein the tapering of the blank in the tapering step is caused by material erosion. ### Claim 20 (depends on 11) The method according to claim 11, wherein the outer fibers are used in the provision step, which are already tapered in the area of the tapered section to be created in the tapering step. ### Claim 21 (depends on 11) The method according to claim 11, wherein the inner tube used in the provision step has a closed internal cross-section for receiving the inner fiber in the area of the tapered section to be created in the tapering step. ### Claim 22 (depends on 11) The method according to claim 11, wherein partial vacuum is used in the tapering step for the tapering.