# US 10,481,339 B2 · High average power optical fiber cladding mode stripper, methods of making and uses > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,339 B2 - Document ID: US10481339B2 - Status: Granted - Kind: B2 - Application number: 15/788,752 - Filed: 2017-10-19 - Published: 2018-02-15 - Granted: 2019-11-19 - Earliest claimed: 2011-06-03 - Assignees: Foro Energy, Inc. - Applicants: Foro Energy, Inc. - Inventors: Ian Lee; Andrey Kuznetsov; Brian O. Faircloth - Web page: https://patentgrep.com/patent/US10481339B2 ## CPC - G02B 6/3813: {for transmission of high energy beam (coupling high energy sources and light guides G02B6/4296)} - G02B 6/14: Mode converters - G02B 6/3814: {with cooling or heat dissipation means} - G02B 6/3818: {of a low-reflection-loss type (G02B6/3813 takes precedence)} - G02B 6/4296: {coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources} - G02B 6/4427: {Pressure resistant cables, e.g. undersea cables} - G02B 2006/4297: {having protection means, e.g. protecting humans against accidental exposure to harmful laser radiation} - H01S 3/0064: {Anti-reflection devices, e.g. optical isolaters (absorbing layers for marking or protecting purposes in laser working B23K26/50; magneto-optical non-reciprocal devices G02F1/093, G02F1/0955)} - 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 Nano-particle based mode strippers for removing undesirable laser energy for laser systems. Nano-particle mode strippers having matched indices of refraction to the outer cladding remove cladding light converting it into heat. There are provided fibers having evanescent mode strippers having annular outer cores and claddings. ## Claims ### Claim 1 A high power laser mode stripper in optical communication with an optical fiber and in thermal communication with a heat sink, the mode stripper comprising: a. a carrier medium; b. the carrier medium being in direct physical contact and in optical contact with a cladding layer of an optical fiber; c. the carrier medium having an index of refraction and the outer cladding having an index of refraction; wherein the carrier medium index of refraction is matched to the cladding index of refraction, whereby light from the cladding will propagate into the carrier medium; d. the carrier medium holding a distribution of nano-particles, whereby the distribution of nano-particles is configured to effect the light propagated from the cladding into the carrier medium; and, e. the carrier medium is in thermal contact with a heat sink; f. whereby upon propagation of light from the cladding to the carrier medium, the nano-particles and carrier medium convert the light propagated from the cladding into heat which is transmitted by the carrier medium to the heat sink. ### Claim 2 (depends on 1) The mode stripper of claim 1, wherein the indices of refraction are matched to within about 5% of each other. ### Claim 3 (depends on 1) The mode stripper of claim 1, wherein the indices of refraction are matched to within about 2% of each other. ### Claim 4 (depends on 1) The mode stripper of claim 1, wherein the indices of refraction are matched to within about 1% of each other. ### Claim 5 (depends on 1) The mode stripper of claim 1, wherein the indices of refraction are matched to within about 0.1% of each other. ### Claim 6 (depends on 1) The mode stripper of claim 1, wherein the indices of refraction are the same. ### Claim 7 (depends on 1) The mode stripper of claim 1, wherein the carrier medium is selected from the group consisting of sodium silicate, fused silica, and spinel. ### Claim 8 (depends on 1) The mode stripper of claim 1, wherein the nano-particles have a D50 particle size of about 100 nm to 2000 nm. ### Claim 9 (depends on 1) The mode stripper of claim 1, wherein the nano-particles have a D50 particle size of about 10 nm to 2000 nm. ### Claim 10 (depends on 1) The mode stripper of claim 1, wherein the nano-particles are selected from the group consisting of silica, diamond, spinel, sapphire, and borosilicate glass. ### Claim 11 (depends on 1) The mode stripper of claim 1, wherein the effect on the light propagated from the cladding to the carrier material comprises scattering. ### Claim 12 (depends on 1) The mode stripper of claim 1, wherein the effect on the light propagated from the cladding to the carrier material comprises absorption. ### Claim 13 (depends on 1) The method of claim 1, wherein the nano-particles have a D50 particle size of about 100 nm to 2000 nm. ### Claim 14 A high power laser mode stripper in optical communication with an optical fiber and in thermal communication with a heat sink, the mode stripper comprising: a. a carrier medium; b. the carrier medium being in direct physical contact and in optical contact with a cladding layer of an optical fiber; c. the carrier medium having an index of refraction and the outer cladding having an index of refraction; wherein the carrier medium index of refraction is matched to the cladding index of refraction, whereby light from the cladding will propagate into the carrier medium; d. the carrier medium holding a distribution of nano-particles, whereby the distribution of nano-particles is capable of absorbing and scattering the light propagated from the cladding into the carrier medium; and, e. the carrier medium is in thermal contact with a heat sink; f. whereby the nano-particles are capable of converting the light propagated from the cladding to the carrier medium to heat which is transmitted to the heat sink. ### Claim 15 (depends on 14) The mode stripper of claim 14, wherein at least about 50% of the light propagated from the cladding into the carrier medium is scattered by the nano-particles. ### Claim 16 (depends on 14) The mode stripper of claim 14, wherein at least about 80% of the light propagated from the cladding into the carrier medium is scattered by the nano-particles. ### Claim 17 (depends on 14) The mode stripper of claim 14, wherein about 5% to 20% of the light propagated from the cladding into the carrier medium is absorbed by the nano-particles. ### Claim 18 (depends on 14) The mode stripper of claim 14, wherein at least about 90% of the light propagated from the cladding into the carrier medium is scattered by the nano-particles. ### Claim 19 (depends on 14) The mode stripper of claim 14, wherein the nano-particles have a particle size of about 100 nm to about 2000 nm. ### Claim 20 (depends on 14) The mode stripper of claim 14, wherein the nano-particles have a particle size of about 500 nm to about 1500 nm. ### Claim 21 (depends on 14) The mode stripper of claim 14, wherein the nano-particles have a particle size of about 2000 nm and smaller.