# US 10,502,911 B2 · Laser arrangement with auxiliary ring > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,911 B2 - Document ID: US10502911B2 - Status: Granted - Kind: B2 - Application number: 15/544,723 - Filed: 2016-01-19 - Published: 2018-01-11 - Granted: 2019-12-10 - Earliest claimed: 2015-01-23 - Assignees: JENOPTIK Optical Systems GmbH - Applicants: JENOPTIK Laser GmbH - Inventors: Juergen Wolf - Web page: https://patentgrep.com/patent/US10502911B2 ## CPC - G02B 6/4296: {coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources} - G02B 6/32: having lens focusing means {positioned between opposed fibre ends (with lens being an integral part of the single fibre end G02B6/262)} - G02B 6/3813: {for transmission of high energy beam (coupling high energy sources and light guides G02B6/4296)} - G02B 6/3814: {with cooling or heat dissipation means} - G02B 6/4206: {Optical features (G02B6/4207, G02B6/421 take precedence)} - H01S 5/02251: using optical fibres - H01S 5/4012: {Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms} - H01S 5/4031: {Edge-emitting structures} - G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)} - 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 ## Abstract The invention relates to a transparent auxiliary ring for the adjustment, for the long-term stable operation and for protection of fiber-coupled laser arrangements. ## Claims ### Claim 1 A device for coupling laser radiation into an optical fiber, wherein the optical fiber has a coupling-in end having a fiber end face, comprising a laser beam source which provides a collimated beam bundle, and a focus lens, which has an effective aperture D, a focal length f, an optical axis and a fiber-side lens surface, wherein the focus lens focuses the collimated beam bundle in the direction of the fiber end face into a focus, wherein a transparent auxiliary ring having a ring inner diameter dR and a length lR is provided, wherein the auxiliary ring has an inner lateral surface, an outer lateral surface, a first end surface and a second end surface, wherein the auxiliary ring is arranged in the beam path downstream of the focus lens, and the inner lateral surface is centered with respect to the optical axis (31), and the first end surface is arranged in a first plane situated at a distance s upstream of the focus, and the ring inner diameter dR is less than D·s/f and the length lR of the auxiliary ring is less than the distance s. ### Claim 2 (depends on 1) The device as claimed in claim 1, wherein the auxiliary ring is suitable for reflecting rays coming from the focus lens, said rays being coupled into the auxiliary ring at the first end surface, at the inner lateral surface by means of total internal reflection, wherein the reflected rays, after the reflection, propagate further in the auxiliary ring as far as the second end surface and arrive there with a direction component away from the optical axis. ### Claim 3 (depends on 1) The device as claimed in claim 1, wherein the first end surface bears directly on the fiber-side lens surface and/or is connected to the fiber-side lens surface by wringing. ### Claim 4 (depends on 1) The device as claimed in claim 1, wherein the first end surface is optically coupled to the fiber-side lens surface via a transparent coupling material. ### Claim 5 (depends on 1) The device as claimed in claim 1, wherein the device comprises a focus lens holder, and the auxiliary ring is connected to the focus lens holder via the first end surface and/or the outer lateral surface. ### Claim 6 (depends on 1) The device as claimed in claim 1, wherein the beam bundle of the laser beam source is linearly polarized in a first polarization direction, and the device additionally comprises a second laser beam source, which provides a second collimated beam bundle, which is linearly polarized in a second polarization direction, and the second laser beam bundle is combined with the first beam bundle by means of a beam splitter, such that the second beam bundle is coupled as it were with the first beam bundle into the optical fiber, wherein the beam splitter is arranged in the beam path upstream of the first end surface. ### Claim 7 (depends on 1) The device as claimed in claim 1, wherein the beam bundle of the laser beam source has a first wavelength, and the device additionally comprises a third laser beam source, which provides a third collimated beam bundle, which has a third wavelength, which is different than the first wavelength, and the third laser beam bundle is combined with the first beam bundle by means of a dichroic element, such that the third beam bundle is coupled as it were with the first beam bundle into the optical fiber, wherein the dichroic element is arranged in the beam path upstream of the first end surface. ### Claim 8 (depends on 1) The device as claimed in claim 1, wherein the device has a housing, and the coupling-in end of the optical fiber is connected to the housing, and the focus lens is adjustable relative to the fiber end face. ### Claim 9 (depends on 1) The device as claimed in claim 1, wherein the optical fiber has a first numerical aperture NAF, and the laser radiation is guided in the optical fiber, and the laser radiation has a second numerical aperture NAL, and the second numerical aperture NAL is less than the first numerical aperture NAP. ### Claim 10 (depends on 1) The device as claimed in claim 1, wherein the length ZR of the auxiliary ring is between one tenth and two thirds of the focal length f of the focus lens, and/or in that the auxiliary ring has a wall thickness w, and the wall thickness w is greater than one tenth of the ring inner diameter dR. ### Claim 11 (depends on 1) The device as claimed in claim 1, wherein the outer lateral surface and/or the second end surface are/is embodied and/or coated as light-scattering and/or absorbing surfaces. ### Claim 12 The use of a transparent auxiliary ring having a ring inner diameter dR and a length lR, which auxiliary ring has an inner lateral surface, an outer lateral surface, a first end surface and a second end surface and is suitable for reflecting non-useful light, coupled in at the first end surface, at the inner lateral surface by means of total internal reflection and for coupling out and/or scattering and/or absorbing said light at the second end surface and/or the outer lateral surface, for adjusting and/or for operating and/or for protecting a device for coupling laser radiation into an optical fiber, wherein the device comprises a focus lens having an effective aperture D and a focal length f, wherein the focus lens focuses the laser radiation in the direction of the fiber end face into a focus, wherein the first end surface is arranged in a first plane situated at a distance s upstream of the focus, and the ring inner diameter dR is less than D·s/f, and the inner lateral surface is centered with respect to the optical axis, and the length lR of the auxiliary ring is less than the distance s. ### Claim 13 A method for coupling laser radiation into an optical fiber, wherein the optical fiber has a coupling-in end having a fiber end face, comprising a) providing at least one collimated beam bundle, b) focusing the collimated beam bundle into a focus by means of a focus lens, c) coupling the focused beam bundle into the optical fiber, wherein the focus lens has an effective aperture D, a focal length f, an optical axis and a fiber-side lens surface, wherein a transparent auxiliary ring having a ring inner diameter dR and a length lR is provided, wherein the auxiliary ring has an inner lateral surface, an outer lateral surface, a first end surface and a second end surface, wherein the auxiliary ring is arranged in the beam path downstream of the focus lens, and the first end surface is arranged in a first plane situated at a distance s upstream of the focus, and the ring inner diameter dR is less than D·s/f, and the inner lateral surface is centered with respect to the optical axis, and the length lR of the auxiliary ring is less than the distance s, wherein the auxiliary ring is suitable for reflecting rays, coupled in at the first end surface, at the inner lateral surface by means of total internal reflection and for coupling out and/or scattering and/or absorbing said rays at the second end surface and/or the outer lateral surface.