Rotary optical beam generator

Patent metadata

Field	Value
Publication number	US-10690854-B2
Application number	US-201916582487-A
Country	US
Kind code	B2
Filing date	Sep 25, 2019
Priority date	Nov 22, 2016
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

An optical fiber device may include a unitary core including a primary section and a secondary section, wherein at least a portion of the secondary section is offset from a center of the unitary core, wherein the unitary core twists about an optical axis of the optical fiber device along a length of the optical fiber device, and wherein a refractive index of the primary section is greater than a refractive index of the secondary section; and a cladding surrounding the unitary core.

First claim

What is claimed is:

1. A method, comprising:
fabricating a rotator fiber preform having a unitary core with a refractive index structure that angularly varies with respect to a center of the rotator fiber preform;
consolidating the rotator fiber preform in order to create a consolidated rotator fiber preform;
concurrently drawing and spinning the consolidated rotator fiber preform in order to create a spun rotator fiber; and
tapering the spun rotator fiber in order to create a tapered spun rotator fiber,
wherein, within the tapered spun rotator fiber, the unitary core rotates about an optical axis of the tapered spun rotator fiber along a length of the tapered spun rotator fiber, and
wherein a rate of twist at which the unitary core twists about the optical axis increases from a first rate of twist at a first end of the tapered spun rotator fiber to a second rate of twist at a second end of the tapered spun rotator fiber.

2. The method of claim 1 , further comprising:
splicing the spun rotator fiber to an end of an output fiber prior to tapering the spun rotator fiber.

3. The method of claim 1 , wherein the rotator fiber preform is consolidated during a preforming process associated with fabricating the rotator fiber preform.

4. The method of claim 1 , wherein the rotator fiber preform is consolidated during a drawing and spinning process associated with concurrently drawing and spinning the consolidated rotator fiber preform.

5. The method of claim 1 , further comprising:
securing the consolidated rotator fiber preform in a preform spinner on a fiber draw tower in association with concurrently drawing and spinning the consolidated rotator fiber preform.

6. The method of claim 1 , wherein a rate of spin associated with concurrently drawing and spinning the consolidated rotator fiber preform causes a rate of twist in the spun rotator fiber to be greater than approximately 50 rotations per meter.

7. The method of claim 1 , wherein, as a result of tapering the spun rotator fiber, the tapered spun rotator fiber has a downward taper such that a size of the unitary core tapers down to be approximately equal to a size of a core of an input fiber.

8. The method of claim 1 , wherein, a taper rate, associated with tapering the spun rotator fiber, is selected to cause transitions of light propagating through the tapered spun rotator fiber to be adiabatic or near-adiabatic.

9. The method of claim 1 , further comprising:
splicing the tapered spun rotator fiber onto an end of an input fiber.

10. A method, comprising:
fabricating a rotator fiber preform including a unitary core with a refractive index structure that angularly varies with respect to a center of the rotator fiber preform;
consolidating the rotator fiber preform in order to create a consolidated rotator fiber preform;
drawing the consolidated rotator fiber preform in order to create a drawn rotator fiber; and
twisting the drawn rotator fiber in order to create a twisted rotator fiber,
wherein, within the twisted rotator fiber, the unitary core rotates about an optical axis of the twisted rotator fiber along a length of the twisted rotator fiber, and
wherein a rate of twist at which the unitary core twists about the optical axis increases from a first rate of twist at a first end of the twisted rotator fiber to a second rate of twist at a second end of the twisted rotator fiber.

11. The method of claim 10 , further comprising:
splicing the drawn rotator fiber to an end of an output fiber prior to twisting the drawn rotator fiber.

12. The method of claim 10 , wherein the rotator fiber preform is consolidated during a preforming process associated with fabricating the rotator fiber preform.

13. The method of claim 10 , wherein the rotator fiber preform is consolidated during a drawing process associated with drawing the consolidated rotator fiber preform.

14. The method of claim 10 , further comprising:
softening the drawn rotator fiber with a heat source while twisting the drawn rotator fiber,
wherein the drawn rotator fiber is twisted such that the twisted rotator fiber has a variable twist rate along the length of the twisted rotator fiber.

15. The method of claim 10 , wherein a rate of twist within the twisted rotator fiber is greater than approximately 50 rotations per meter.

16. The method of claim 10 , wherein, as a result of drawing the consolidated rotator fiber preform, the drawn rotator fiber has a downward taper such that a size of the unitary core tapers down to be approximately equal to a size of a core of an output fiber.

17. The method of claim 16 , wherein, a taper rate of the downward taper is selected to cause transitions of light propagating through the twisted rotator fiber to be adiabatic or near-adiabatic.

18. The method of claim 10 , further comprising:
splicing the twisted rotator fiber onto an end of an input fiber.

19. The method of claim 10 , wherein the twisted rotator fiber has a rate of twist that varies from zero or near zero at an input end of the twisted rotator fiber to a non-zero rate of twist at an output end of the twisted rotator fiber.

20. The method of claim 10 , wherein a size of the twisted rotator fiber at an input end matches a size of an input fiber and a size of the twisted rotator fiber at an output end matches a sized of an output fiber.

Assignees

• Lumentum Operations Llc

Inventors

• Muendel Martin H
• Morehead James J

Classifications

• G02B6/2726

  in or on light guides, e.g. polarisation means assembled in a light guide · 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

• G02B6/262

  Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements · CPC title

• G02B6/14 Primary

  Mode converters · CPC title

• G02B6/105

  having optical polarisation effects · CPC title