US 12,240,778 B2
Methods for producing a hollow-core fiber and for producing a preform for a hollow-core fiber
Manuel Rosenberger, Hanau (DE); Ralph Sattmann, Hanau (DE); Achim Hofmann, Hanau (DE); Michael Hünermann, Hanau (DE); and Kay Schuster, Hanau (DE)
Assigned to HERAEUS QUARZGLAS GMBH & CO. KG, Hanau (DE)
Appl. No. 17/617,487
Filed by HERAEUS QUARZGLAS GMBH & CO. KG, Hanau (DE)
PCT Filed Jul. 15, 2020, PCT No. PCT/EP2020/069977
§ 371(c)(1), (2) Date Dec. 8, 2021,
PCT Pub. No. WO2021/009211, PCT Pub. Date Jan. 21, 2021.
Claims priority of application No. 19186741 (EP), filed on Jul. 17, 2019.
Prior Publication US 2022/0234936 A1, Jul. 28, 2022
Int. Cl. C03B 37/027 (2006.01); C03B 37/012 (2006.01); G02B 6/02 (2006.01)
CPC C03B 37/02781 (2013.01) [C03B 37/0122 (2013.01); C03B 37/0124 (2013.01); G02B 6/02328 (2013.01); G02B 6/02395 (2013.01); C03B 2203/16 (2013.01); C03B 2203/42 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for producing an anti-resonant hollow-core fiber comprising a hollow core extending along a longitudinal axis of the fiber and a sheath region surrounding the hollow core and comprising a plurality of anti-resonance elements, the method comprising:
(a) providing a cladding tube comprising an inner bore of the cladding tube and a longitudinal axis of the cladding tube, along which a cladding tube wall delimited by an inner side and an outer side extends,
(b) providing a number of anti-resonance element preforms composed of a plurality of nested structural elements,
(c) arranging the anti-resonance element preforms at setpoint positions of the inner side of the cladding tube wall to form a primary preform for the hollow-core fiber, which comprises a hollow core region and a sheath region, and
(d) elongating the primary preform to form the hollow-core fiber or further processing the primary preform into a secondary preform from which the hollow-core fiber is drawn, wherein the further processing comprises a single or repeated performance of one or more of the following hot-forming processes:
(i) elongation,
(ii) collapse,
(iii) collapse and simultaneous elongation,
(iv) collapse of additional sheath material,
(v) collapse of additional sheath material and subsequent elongation,
(vi) collapse of additional sheath material and simultaneous elongation,
wherein the provision of the anti-resonance element preforms comprises a fixing measure,
wherein the nested structural elements are fixed with respect to one another using a sealing or bonding compound containing amorphous SiO2 particles obtained by wet milling grains of high-purity silica glass, and wherein the sealing or bonding compound is vitrified by heating during a hot forming process according to process step (d).