US 12,189,177 B2
Methods for producing a hollow-core fiber and for producing a preform for a hollow-core fiber
Manuel Rosenberger, Hanau (DE); Martin Trommer, Hanau (DE); Steffen Weimann, Hanau (DE); Michael Hünermann, Hanau (DE); and Kay Schuster, Hanau (DE)
Assigned to HERAEUS QUARZGLAS GMBH & CO. KG, Hanau (DE)
Appl. No. 17/619,980
Filed by HERAEUS QUARZGLAS GMBH & CO. KG, Hanau (DE)
PCT Filed Jul. 15, 2020, PCT No. PCT/EP2020/069992
§ 371(c)(1), (2) Date Dec. 16, 2021,
PCT Pub. No. WO2021/009220, PCT Pub. Date Jan. 21, 2021.
Claims priority of application No. 19186861 (EP), filed on Jul. 17, 2019.
Prior Publication US 2022/0357506 A1, Nov. 10, 2022
Int. Cl. G02B 6/02 (2006.01); C03B 37/012 (2006.01); C03B 37/027 (2006.01); G02B 6/032 (2006.01)
CPC G02B 6/02328 (2013.01) [C03B 37/01245 (2013.01); C03B 37/01262 (2013.01); C03B 37/02781 (2013.01); G02B 6/032 (2013.01); C03B 2201/02 (2013.01); C03B 2203/16 (2013.01)] 15 Claims
OG exemplary drawing
 
15. A method for producing a preform for an anti-resonant hollow-core fiber having a hollow core extending along a longitudinal axis of the hollow-core fiber and an inner sheath surrounding the hollow core, which inner sheath includes a plurality of anti-resonance elements, the method comprising the steps of:
(a) providing a cladding tube having an inner bore and a longitudinal axis, along which a cladding tube wall delimited by an inner side and an outer side extends;
(b) providing a plurality of tubular anti-resonance element preforms;
(c) arranging the anti-resonance element preforms at desired positions of the inner side of the cladding tube wall to form a primary preform having an outer diameter in the range of 20 to 70 mm; and
(d) further processing the primary preform into a secondary preform for the hollow-core fiber, wherein the further processing includes elongating the primary preform and
(i) collapsing additional sheath material,
(ii) collapsing additional sheath material and simultaneously elongating the primary preform such that the resulting secondary preform has an outside diameter in the range of 20 to 70 mm, further comprising fixing and/or sealing using a sealing or bonding compound containing amorphous SiO2 particles to arrange the anti-resonance element preforms and/or elongate the primary preform and/or draw the hollow-core fiber, and
wherein open ends of the anti-resonance element preforms and/or individual structural elements of the anti-resonance element preforms and/or any annular gap between tube elements of the anti-resonance element preforms are sealed by the sealing or bonding compound when the primary preform is elongated and/or when the hollow-core fibers are drawn.