Method and apparatus for implementing a rectangular-core laser beam-delivery fiber that provides two orthogonal transverse bending degrees of freedom

Patent metadata

Field	Value
Publication number	US-9664869-B2
Application number	US-201113308812-A
Country	US
Kind code	B2
Filing date	Dec 1, 2011
Priority date	Dec 1, 2011
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

In various embodiments, an optical fiber module including an optical fiber having a first end, a second end, and a twisted portion between the first and second ends to enable the optical fiber to provide two orthogonal transverse bending degrees of freedom. The twisted portion induces an optical distortion. The module further includes a distortion compensation arrangement that is configured to at least partially compensate for the optical distortion and a housing that is configured to house at least a portion of the optical fiber including the twisted portion.

First claim

What is claimed:

1. An optical fiber module comprising:
an optical fiber having a first end, a second end, and a twisted portion between the first and second ends to enable the optical fiber to provide two orthogonal transverse bending degrees of freedom, wherein the twisted portion induces an optical distortion, wherein a width dimension of the optical fiber in a cross section of the twisted portion at a first point of the twisted portion is substantially orthogonal to the width dimension of the optical fiber in a cross section of the twisted portion at a second point of the twisted portion;
a distortion compensation arrangement configured to at least partially compensate for the optical distortion resulting from the twisted portion, the distortion compensation arrangement comprising (i) at least one first cylindrical lens configured to collimate and direct a laser beam towards the twisted portion, (ii) at least one second cylindrical lens configured to apply convergence of beam energy in a slow-axis direction towards the second end, (iii) at least one third cylindrical lens configured to image the laser beam in the slow-axis direction into an output fiber, and (iv) at least one fourth cylindrical lens configured to collimate the laser beam in a fast-axis direction and direct the laser beam into the output fiber; and
a housing configured to house at least a portion of the optical fiber including the twisted portion.

2. The optical fiber module of claim 1 , wherein:
the first end is configured to be operatively connected to an input fiber; and
the second end is configured to be operatively connected to an output fiber.

3. The optical fiber module of claim 2 , wherein the at least one first cylindrical lens and the at least one second cylindrical lens are disposed before the first end and the twisted portion.

4. The optical fiber module of claim 1 , wherein:
the optical distortion appears as a distortion of a polarization state; and
the distortion compensation arrangement further comprises at least one polarization component configured to compensate for the polarization distortion resulting from the twisted portion.

5. The optical fiber module of claim 4 , wherein the at least one polarization component comprises a wave plate.

6. The optical fiber module of claim 1 , wherein the housing is a hermetically sealed housing.

7. The optical fiber module of claim 1 , wherein the twisted portion comprises a 90 degree twist.

8. The optical fiber module of claim 1 , wherein the optical distortion is provided by a negative lens effect.

9. The optical fiber module of claim 8 , wherein the distortion compensation arrangement comprises a positive lens effect that has an opposite and substantially equal lens power to a power of the negative lens effect.

10. The optical fiber module of claim 9 , wherein:
the optical fiber comprises a core; and
the positive lens effect is created by producing a slow-axis refractive index variation into the core.

11. The optical fiber module of claim 9 , wherein:
the optical fiber comprises a core; and
the positive lens effect is created by profiling a thickness of the core along the slow-axis direction so the core is thicker at a middle thereof and narrower near edges of the core.

12. The optical fiber module of claim 1 , further comprising an end mount arrangement configured to adjust a length of the twisted portion.

13. The optical fiber module of claim 12 , wherein the end mount arrangement comprises two end mounts configured to be slideable relative to each other so as to adjust a length of the twisted portion.

14. The optical fiber module of claim 13 , wherein the end mounts are constructed and arranged to be fixed relative to each other so as to fix the length of the twisted portion.

15. The optical fiber module of claim 14 , wherein the end mounts are bonded to the housing so as to fix the length of the twisted portion.

16. The optical fiber module of claim 1 , wherein the optical fiber module is divided into a plurality of segments, each of the plurality of segments having a selected length.

17. The optical fiber module of claim 16 , wherein at least one of the plurality of segments includes the twisted portion of the optical fiber.

18. The optical fiber module of claim 17 , wherein two of the plurality of segments include twisted portions each having a 45 degree twist thereby providing a total twist of 90 degrees.

19. The optical fiber module of claim 18 , further comprising an end mount arrangement configured to adjust a length of the twisted portion.

20. The optical fiber module of claim 19 , wherein the end mount arrangement comprises two end mounts configured to be slideable relative to each other so as to adjust the length of the twisted portion.

21. The optical fiber module of claim 20 , wherein the end mounts are constructed and arranged to be fixed relative to each other so as to fix the length of the twisted portion.

22. The optical fiber module of claim 17 , wherein each of the plurality of segments is twisted and includes a twisted portion, each twisted portion of each of the plurality of segments having an amount of twist such that a sum of all amounts of twists in the plurality of segments is equal to 90 degrees.

23. The optical fiber module of claim 22 , further comprising an end mount arrangement configured to adjust a length of the twisted portion in at least one of the segments.

24. The optical fiber module of claim 23 , wherein the end mount arrangement comprises two end mounts configured to be slideable relative to each other so as to adjust the length of the twisted portion in the at least one of the segments.

25. The optical fiber module of claim 24 , wherein the end mounts are constructed and arranged to be fixed relative to each other so as to fix the length of the twisted portion in the at least one of the segments.

Assignees

• Mcvey Ray E
• Rockwell David A
• Raytheon Co

Inventors

• Mcvey Ray E
• Rockwell David A

Classifications

• G02B6/44 Primary

  Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables (cables incorporating electric conductors and optical fibres {where features relating to the optical fibres are not of interest} H01B11/22) · CPC title

• Y10T29/49

  Method of mechanical manufacture · CPC title