Optical fiber splice encapsulated by a cladding light stripper

Patent metadata

Field	Value
Publication number	US-11808973-B2
Application number	US-202117322777-A
Country	US
Kind code	B2
Filing date	May 17, 2021
Priority date	Sep 10, 2018
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

Spliced multi-clad optical fibers with a cladding light stripper (CLS) encapsulating the splice. The splice may facilitate conversion between two optical fibers having different architectures, such as different core and/or cladding dimensions. The CLS may comprise a first length of fiber on a first side of the splice, and a second length of fiber on a second side of the splice, encapsulating the splice within the lengths of the CLS. The splice may abut one or more of the lengths of the CLS, or may be separated from one or more lengths of the CLS by an intermediate length of a first and/or second fiber joined by the splice.

First claim

What is claimed is:

1. A cladding light stripper (CLS) system, comprising:
a first multi-clad fiber providing a first length of fiber having a first cladding, the first cladding including a first outer diameter;
a second multi-clad fiber providing a second length of fiber having a second cladding, the second cladding including a second outer diameter that is different from the first outer diameter, the second multi-clad fiber including outer surface structures formed in the second cladding and configured to strip light therefrom; and
a splice coupling the first length of fiber on a first side of the splice to the second length of fiber on a second side of the splice, in which the splice establishes a stepdown cladding having a glass-air interface between the first outer diameter and the second outer diameter, in which the glass-air interface is configured to direct cladding light away from the splice, wherein the outer surface structures are configured to strip core light scattered by the splice and entering the second cladding at the splice.

2. The CLS system of claim 1 , wherein:
the first multi-clad fiber comprises a first core of a first core diameter;
the second multi-clad fiber comprises a second core of a second core diameter; and
the first and second core diameters are different from each other.

3. The CLS system of claim 1 , wherein:
the first multi-clad fiber comprises a first core of a first core diameter;
the second multi-clad fiber comprises a second core of a second core diameter; and
the first and second core diameters are the same.

4. The CLS of claim 1 , wherein:
the first cladding includes a first inner diameter;
the second cladding includes a second inner diameter; and
the first and second inner diameters are the same.

5. The CLS system of claim 1 , wherein:
the first cladding includes a first inner diameter;
the second cladding includes a second inner diameter; and
the first and second inner diameters are different.

6. The CLS system of claim 1 , wherein the first multi-clad fiber is a first double clad fiber and the second multi-clad fiber is a second double clad fiber.

7. The CLS system of claim 1 , wherein the first and second cladding are inner cladding layers coupled by the splice.

8. The CLS system of claim 1 , further comprising a CLS along the second length of multi-clad fiber, the second CLS configured to receive at least a portion of the cladding light.

9. The CLS system of claim 1 , further comprising a CLS having one or more materials or structures within the first length of multi-clad fiber and within the second length of multi-clad fiber, the one or more materials or structures operable to remove cladding light out of the first and second lengths of multi-clad fiber.

10. The CLS of claim 9 , wherein the CLS comprises one or more structures within the first length of multi-clad fiber and within the second length of multi-clad fiber, and wherein the structures comprise a cladding surrounding a core, the cladding surrounded by free space.

11. The CLS system of claim 9 , wherein the one or more materials or structures are to guide or scatter cladding light out of the first and second lengths of multi-clad fiber.

12. The CLS system of claim 9 , further comprising a housing to contain the CLS and the splice, wherein the first and the second lengths of multi-clad fiber exit the housing.

13. The CLS system of claim 1 , wherein the first length of multi-clad fiber is between the splice and a laser, and the second length of multi-clad fiber is between the splice and a delivery fiber.

14. The CLS system of claim 1 , wherein the first length of multi-clad fiber is between the splice and a laser, and the second length of multi-clad fiber is between the splice and a signal combiner.

15. A laser system including the CLS system of claim 1 , the laser system further comprising a source laser coupled to the first multi-clad fiber.

16. The laser system of claim 15 , wherein the source laser has a power output of at least 3 KW.

17. The CLS system of claim 1 , further comprising a heat exchanger configured to transfer heat from the cladding light directed away from the splice and the light stripped from the second cladding.

18. A method of splicing two multi-clad fibers, the method comprising:
receiving a first of the fibers having a first end, wherein the first fiber has a first cladding of a first outer diameter;
receiving a second of the fibers having a second end, wherein the second fiber has a second cladding of a second outer diameter;
forming outer surface structures in the second cladding to configure the outer surface structures to strip cladding light from the second fiber;
joining the first end to the second end at a splice to establish a stepdown cladding having a glass-air interface between the first outer diameter and the second outer diameter, wherein the glass-air interface is configured to direct cladding light away from the splice; and
forming a cladding light stripper (CLS) including the splice and the outer surface structures, and wherein the outer surface structures are configured to strip core light scattered by the splice and entering the second cladding at the splice.

19. The method of claim 18 , wherein forming the CLS further comprises:
exposing an inner cladding layer by removing an outer cladding layer surrounding the inner cladding layer along the first length and along the second length; and
forming one or more structures in the inner cladding layer, operable to remove cladding light.

20. The method of claim 18 , wherein the first and second fibers have the same core sizes.

21. The method of claim 18 , wherein the first and second fibers are double clad fibers.

22. The method of claim 18 , further comprising housing the CLS with a heat exchanger configured to transfer heat from the cladding light directed away from the splice and the cladding light stripped from the second cladding.

Assignees

• Nlight Inc

Inventors

• Hawke Ryan
• Kokki Teemu
• Hampton Shaun
• Luetjen Chris

Classifications

• G02B6/036 Primary

  core or cladding comprising multiple layers {(multicore optical fibres G02B6/02042; microstructured properties G02B6/02295; omniguide fibres G02B6/023)} · CPC title

• G02B6/245

  Removing protective coverings of light guides before coupling · CPC title

• G02B6/2558

  Reinforcement of splice joint · CPC title

• H01S3/06708

  Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering (optical fibres as passive waveguides G02B6/02) · CPC title

• H01S3/094007 Primary

  Cladding pumping, i.e. pump light propagating in a clad surrounding the active core · CPC title