Methods for producing a hollow-core fiber and for producing a preform for a hollow-core fiber
AssigneeHeraeus Quarzglas GmbH & Co. KG
InventorsManuel Rosenberger, Ralph Sattmann
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Abstract
A high degree of precision and an exact positioning of anti-resonant elements in a sufficiently stable and reproducible manner is achieved in that a step of providing a cladding tube includes a processing measure, in which the cladding tube wall is machined with a longitudinal structure extending in the direction of the cladding tube longitudinal axis in the region of the target positions.
Claims11
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,
- (c) arranging the anti-resonance element preforms at desired positions of the inner side of the cladding tube wall to form a primary preform for the hollow-core fiber which comprises the hollow core region and the 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 cladding tube according to method step (a) comprises a machining measure in which by machining in the region of the desired positions, the cladding tube wall is provided with a longitudinal structure extending in the direction of the longitudinal axis of the cladding tube, wherein the longitudinal structure has longitudinal slots distributed about the circumference of the cladding tube wall, and the anti-resonance element preforms are arranged on one longitudinal slot in each case.
A method for producing a preform for 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, said sheath region 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,
- (c) arranging the anti-resonance element preforms at desired positions of the inner side of the cladding tube wall to form a primary preform for the hollow-core fiber which comprises the hollow core region and the sheath region, and
- (d) optionally further processing the primary preform into a secondary preform for the hollow-core fiber, 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 cladding tube according to method step (a) comprises a machining measure in which, by machining in the region of the desired positions, the cladding tube wall is provided with a longitudinal structure extending in the direction of the longitudinal axis of the cladding tube, wherein the longitudinal structure has longitudinal slots distributed about the circumference of the cladding tube wall, and the anti-resonance element preforms are arranged on one longitudinal slot in each case.
Dependencies are inferred from the claim text.