# US 11,999,645 B2 · Optical fibers and production methods therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,645 B2 - Document ID: US11999645B2 - Status: Granted - Kind: B2 - Application number: 17/287,015 - Filed: 2019-10-03 - Published: 2021-12-16 - Granted: 2024-06-04 - Earliest claimed: 2018-10-24 - Assignees: ASML Netherlands B.V. - Applicants: Asml Netherlands B.V. - Inventors: Robbert Edgar Van Leeuwen; Amir Abdolvand - Web page: https://patentgrep.com/patent/US11999645B2 ## CPC - C03B 37/0122: {for making preforms of photonic crystal, microstructured or holey optical fibres} - C03B 37/01228: {Removal of preform material (C03B37/01251 takes precedence)} - C03B 37/02781: {Hollow fibres, e.g. holey fibres} - C03C 25/68: by etching - G01N 21/956: Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G02B 6/02328: {Hollow or gas filled core} - G02F 1/3528: {for producing a supercontinuum} - G02F 1/365: in an optical waveguide structure (G02F1/377, {G02F1/395} take precedence) - G03F 7/70041: {by pulsed sources, e.g. multiplexing, pulse duration, interval control or intensity control} - G03F 7/70316: {Details of optical elements, e.g. of Bragg reflectors, extreme ultraviolet [EUV] multilayer or bilayer mirrors or diffractive optical elements} - G03F 7/70575: {Wavelength control, e.g. control of bandwidth, multiple wavelength, selection of wavelength or matching of optical components to wavelength} - G03F 7/70616: {Monitoring the printed patterns} - C03B 2203/14: Non-solid, i.e. hollow products, e.g. hollow clad or with core-clad interface - C03B 2203/16: Hollow core - C03B 2203/42: Photonic crystal fibres, e.g. fibres using the photonic bandgap PBG effect, microstructured or holey optical fibres - G01N 2021/8809: {Adjustment for highlighting flaws} - Y02P 40/57: Improving the yield, e-g- reduction of reject rates - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An optical fiber, manufacturing intermediate for forming an optical fiber and a method for forming an optical fiber. The method includes providing a manufacturing intermediate having an elongate body and having an aperture extending through the elongate body along an axial dimension of the elongate body, a boundary of the aperture defining an internal surface of the manufacturing intermediate. The method further includes etching the internal surface of the manufacturing intermediate using an etching substance, and drawing the manufacturing intermediate along the axial dimension so as to form the optical fiber. ## Claims ### Claim 1 A method for forming an optical fiber, the method comprising: providing a manufacturing intermediate having an elongate body and comprising an outer tube and a plurality of inner tubes, the plurality of inner tubes being arranged in the outer tube, the plurality of inner tubes being arranged in one or more ring structures around, and at least partially defining, an aperture extending through the elongate body along an axial dimension of the elongate body, a boundary of the aperture defining an internal surface of the manufacturing intermediate; etching the internal surface of the manufacturing intermediate using an etching substance; and drawing the manufacturing intermediate along the axial dimension so as to form the optical fiber, the optical fiber being a hollow-core anti-resonant-reflecting fiber comprising a plurality of anti-resonant elements formed from the inner tubes. ### Claim 2 (depends on 1) The method according to claim 1, wherein the plurality of inner tubes are arranged around a hollow core so that each of the inner tubes is not in direct contact with any of the other inner tubes. ### Claim 3 (depends on 1) The method according to claim 1, by drawing the manufacturing intermediate along an axial dimension, dimensions of the manufacturing intermediate perpendicular to the axial dimension are reduced by a factor, wherein the factor is at least 10. ### Claim 4 (depends on 1) The method according to claim 1, wherein the etching of the internal surface of the manufacturing intermediate comprises a wet chemical etching process. ### Claim 5 (depends on 4) The method according to claim 4, wherein etching of the internal surface of the manufacturing intermediate comprises liquid submerging, capillary filling, pressurized filling, or spray etching. ### Claim 6 (depends on 1) The method according to claim 1, wherein the etching substance comprises HF, a mixture of HF and HNO3, or KOH. ### Claim 7 (depends on 1) The method according to claim 1, wherein the method is performed at room temperature. ### Claim 8 (depends on 1) The method according to claim 1, wherein the etching of the internal surface of the manufacturing intermediate comprises a dry chemical etch. ### Claim 9 (depends on 1) The method according to claim 1, further comprising etching an internal surface of one or more of the inner tubes of the manufacturing intermediate using the etching substance. ### Claim 10 (depends on 1) The method according to claim 1, wherein the etching the internal surface of the manufacturing intermediate comprises preferentially etching one or more portions of the internal surface of the manufacturing intermediate which correspond to one or more portions of the optical fiber that, in use, have dominant contact or interaction with radiation propagating through the optical fiber. ### Claim 11 (depends on 1) An optical fiber formed according to the method of claim 1. ### Claim 12 (depends on 1) A supercontinuum radiation source comprising: a radiation source operable to produce a radiation beam; and an optical fiber formed according to the method of claim 1, wherein the optical fiber is configured to receive the radiation beam and to broaden a spectrum of that radiation beam so as to generate a supercontinuum radiation beam. ### Claim 13 (depends on 1) A lithographic apparatus comprising an optical fiber formed according to the method of claim 1. ### Claim 14 (depends on 1) A metrology apparatus comprising an optical fiber formed according to the method of claim 1. ### Claim 15 A method for producing a manufacturing intermediate to form an optical fiber, the method comprising: providing a manufacturing intermediate having an elongate body and comprising an outer tube and a plurality of inner tubes, the plurality of inner tubes being arranged in the outer tube, the plurality of inner tubes being arranged in one or more ring structures around, and at least partially defining, an aperture extending through the elongate body along an axial dimension of the elongate body, a boundary of the aperture defining an internal surface of the manufacturing intermediate; and etching the internal surface of the manufacturing intermediate using an etching substance. ### Claim 16 (depends on 15) The method according to claim 15, wherein the etching of the internal surface of the manufacturing intermediate comprises a wet chemical etching process, and the etching of the internal surface of the manufacturing intermediate comprises liquid submerging, capillary filling, pressurized filling, or spray etching. ### Claim 17 (depends on 15) The method according to claim 15, wherein the etching substance comprises HF, a mixture of HF and HNO3, or KOH. ### Claim 18 (depends on 15) The method according to claim 15, wherein the method is performed at room temperature. ### Claim 19 (depends on 15) The method according to claim 15, further comprising etching an internal surface of one or more of the inner tubes of the manufacturing intermediate using the etching substance. ### Claim 20 (depends on 15) The method according to claim 15, wherein the plurality of inner tubes are arranged around a hollow core so that each of the inner tubes is not in direct contact with any of the other inner tubes. ### Claim 21 (depends on 15) A manufacturing intermediate for forming an optical fiber, the manufacturing intermediate formed according to the method of claim 15.