Granted Patent B2

US 12,498,517 · App. 18/770,197 · Granted Dec 16, 2025

Inventors: Stuart Campbell (Lindome, SE); Rasmus Kihlberg (Gothenburg, SE); Mats Blomqvist (Sävedalen, SE)

Assignee: Optoskand AB

G02B6/02328G02B6/255

Abstract

Claims (23)

1 . A method for terminating a hollow-core optical fiber, comprising steps of:

positioning a first end of a hollow-core optical fiber, having a structured cladding, in a bore of a capillary such that the first end of the hollow-core optical fiber terminates inside the capillary a non-zero distance away from a first end face of the capillary, the bore being defined by an inner cylindrical surface of the capillary, the inner cylindrical surface extending from the first end face to a second end face of the capillary, the first and second end facing in mutually-opposite directions;

after the positioning step, adhering the hollow-core optical fiber to the capillary at the second end face of the capillary where the hollow-core optical fiber extends out of the capillary; and

laser welding an endcap to the first end face of the capillary, the endcap having a larger diameter than the first end of the hollow-core optical fiber and being directly abutted to the first end face.

2 . The method of claim 1 , wherein the laser welding step is performed after the positioning step.

3 . The method of claim 2 , wherein the positioning step includes steps of:

inserting the first end of the hollow-core optical fiber into the bore of the capillary;

cleaving the hollow-core optical fiber and capillary together such that the first end of the hollow-core optical fiber terminates at the first end face of the capillary formed by said cleaving; and

pulling the hollow-core optical fiber back from the first end face of the capillary such that the first end of the hollow-core optical fiber terminates inside the capillary a non-zero distance away from the first end face.

4 . The method of claim 1 , wherein the laser welding step is performed after the adhering step.

5 . The method of claim 1 , wherein the laser welding step is performed before the positioning step.

6 . The method of claim 1 , further comprising a step of stripping a jacket from the first end of the hollow-core fiber before the positioning step.

7 . The method of claim 1 , further comprising steps of:

prior to the positioning step, inserting the hollow-core optical fiber into a housing, via a first end of the housing, such that the hollow-core optical fiber protrudes from a second end of the housing opposite the first end; and

after the laser welding step, shifting the housing along the hollow-core optical fiber toward the endcap such that the endcap contacts the housing at the second end.

8 . The method of claim 7 , further comprising sealing the first and second ends of the housing after the shifting step.

9 . The method of claim 1 , wherein the non-zero distance between the first end of the hollow-core optical fiber and the first end face of the capillary is in the range between 50 and 200 micrometers.

10 . The method of claim 9 , wherein the inner cylindrical surface has a diameter in the range between 60 and 240 micrometers.

11 . The method of claim 1 , the first and second end faces of the capillary are at least 10 millimeters apart from each other.

12 . The method of claim 1 , wherein the capillary is a cylinder with a cylindrical outer surface.

13 . The method of claim 1 , wherein the hollow-core fiber includes:

a solid outer wall forming a radially outermost surface of the first end of the hollow-core fiber; and

a structured cladding inside the solid outer wall to guide light in a hollow core surrounded by the structured cladding.

Assignments (1)

Continuity (2)

References Cited (11)