Fiber coupler

Patent metadata

Field	Value
Publication number	US-11029467-B2
Application number	US-201916587834-A
Country	US
Kind code	B2
Filing date	Sep 30, 2019
Priority date	Oct 11, 2018
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A method may include performing an active alignment to enable optical coupling between a first optical fiber and a second optical fiber via an imaging structure. An end of the first optical fiber may be at a first location on a first surface of the imaging structure. The first location may be a first transverse offset distance from an axis of the imaging structure. An end of the second optical fiber may be at a second location of the first surface of the imaging structure. The second location may be a second transverse offset distance from the axis of the imaging structure. The method may include fusion splicing the end of the first optical fiber at the first location on the first surface of the imaging structure, and fusion splicing the end of the second optical fiber at the second location on the first surface of the imaging structure.

First claim

What is claimed is:

1. A method, comprising:
providing a first optical fiber and a second optical fiber such that an end of the first optical fiber is at a fixed position with respect to an end of the second optical fiber;
performing an active alignment to enable optical coupling between the first optical fiber and the second optical fiber via a curved endcap structure with a fixed refractive index,
wherein a center of curvature of the curved endcap structure is located on a first surface of the curved endcap structure, and
wherein, as a result of the active alignment:
an end of the first optical fiber is at a first location on the first surface of the curved endcap structure,
wherein the first location is at a first transverse offset distance from an axis of the curved endcap structure, and

an end of the second optical fiber is at a second location of the first surface of the curved endcap structure,
wherein the second location is at a second transverse offset distance from the axis of the curved endcap structure; and

concurrently fusion splicing the end of the first optical fiber at the first location on the first surface and the end of the second optical fiber at the second location on the first surface,
wherein at least one of:
the curved endcap structure is formed from undoped fused silica, or
the first optical fiber is a pump input fiber and the second optical fiber is an amplifier fiber.

2. The method of claim 1 , wherein the concurrent fusion splicing of the end of the first optical fiber at the first location and the end of the second optical fiber at the second location is performed using a single heat source.

3. The method of claim 1 , further comprising:
packaging the first optical fiber, the second optical fiber, and the curved endcap structure to provide strain relief or heatsinking.

4. The method of claim 1 , wherein the curved endcap structure is formed from the undoped fused silica.

5. The method of claim 1 , wherein the first transverse offset distance matches the second transverse offset distance.

6. The method of claim 1 , wherein the first optical fiber is the pump input fiber and the second optical fiber is the amplifier fiber.

7. The method of claim 6 , wherein the curved endcap structure comprises a dichroic coating at a second surface of the curved endcap structure.

8. The method of claim 6 , wherein the pump input fiber is a multimode fiber and the amplifier fiber is a double-clad fiber or a triple-clad fiber.

9. The method of claim 6 , wherein the pump input fiber and the amplifier fiber are single-clad and single-mode fibers.

10. A method, comprising:
fusion splicing an end of a first optical fiber at a first location on a first surface of a curved endcap structure with a fixed refractive index,
wherein a center of curvature of the curved endcap structure is located on the first surface of the curved endcap structure, and
wherein the first location is at a first transverse offset distance from an axis of the curved endcap structure;

performing an active alignment to enable optical coupling between the first optical fiber and a second optical fiber via the curved endcap structure,
wherein, as a result of the active alignment, an end of the second optical fiber is at a second location on the first surface of the curved endcap structure,
wherein the second location is at a second transverse offset distance from the axis of the curved endcap structure; and

fusion splicing the end of the second optical fiber at the second location on the first surface of the curved endcap structure,
wherein at least one of:
the curved endcap structure is formed from undoped fused silica, or
the first optical fiber is a pump input fiber and the second optical fiber is an amplifier fiber.

11. The method of claim 10 , wherein the fusion splicing of the end of the first optical fiber at the first location and the fusion splicing of the end of the second optical fiber at the second location is performed using a carbon dioxide laser.

12. The method of claim 10 , further comprising:
packaging the first optical fiber, the second optical fiber, and the curved endcap structure to provide strain relief or heatsinking.

13. The method of claim 10 , wherein the first transverse offset distance matches the second transverse offset distance.

14. The method of claim 10 , wherein the first optical fiber is the pump input fiber and the second optical fiber is the amplifier fiber.

15. A method, comprising:
performing an active alignment to enable optical coupling between a first optical fiber and a second optical fiber via a curved endcap structure with a fixed refractive index,
wherein a center of curvature of the curved endcap structure is located on a first surface of the curved endcap structure,
wherein an end of the first optical fiber is at a first location on the first surface of the curved endcap structure,
the first location being at a first transverse offset distance from an axis of the curved endcap structure, and

wherein an end of the second optical fiber is at a second location on the first surface of the curved endcap structure,
the second location being at a second transverse offset distance from the axis of the curved endcap structure;

fusion splicing the end of the first optical fiber at the first location on the first surface of the curved endcap structure; and
fusion splicing the end of the second optical fiber at the second location on the first surface of the curved endcap structure,
wherein at least one of:
the curved endcap structure is formed from undoped fused silica, or
the first optical fiber is a pump input fiber and the second optical fiber is an amplifier fiber.

16. The method of claim 15 , wherein the fusion splicing of the end of the first optical fiber at the first location and the end of the second optical fiber at the second location is performed using a single heat source.

17. The method of claim 15 , further comprising:
packaging the first optical fiber, the second optical fiber, and the curved endcap structure to provide strain relief or heatsinking.

18. The method of claim 15 , wherein the curved endcap structure is formed from the undoped fused silica.

19. The method of claim 15 , wherein the first transverse offset distance matches the second transverse offset distance.

20. The method of claim 15 , wherein the first optical fiber is the pump input fiber and the second optical fiber is the amplifier fiber.

Assignees

• Lumentum Operations Llc

Inventors

• Muendel Martin H
• Faulhaber Richard D
• Lefort James
• Morehead James J
• Petit Vincent
• Pierrot Simonette
• Schneider Kyle R

Classifications

• G02B6/32 Primary

  having lens focusing means {positioned between opposed fibre ends (with lens being an integral part of the single fibre end G02B6/262)} · CPC title

• G02B6/255 Primary

  Splicing of light guides, e.g. by fusion or bonding · CPC title

• G02B6/264

  with optical elements between opposed fibre ends which perform a function other than beam splitting (having lens focusing means G02B6/32; utilising prism or grating G02B6/34) · CPC title

• G02B6/2551 Primary

  using thermal methods, e.g. fusion welding by arc discharge, laser beam, plasma torch · CPC title

• C03B2201/06

  Doped silica-based glasses · CPC title