Polarization scrambler using a retardance element

Patent metadata

Field	Value
Publication number	US-11754862-B2
Application number	US-202217979114-A
Country	US
Kind code	B2
Filing date	Nov 2, 2022
Priority date	Jun 10, 2019
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization to scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

First claim

The invention claimed is:

1. A polarization scrambler comprising:
an optical fiber input to transmit an optical signal;
a beam expander to expand the optical signal from the optical fiber input into an expanded optical signal;
a patterned retarder to receive the expanded optical signal from the beam expander and including a plurality of different patterns to cause different parts of the expanded optical signal from the beam expander to encounter different amounts of birefringence to produce a polarization scrambling effect on the expanded optical signal to create a scrambled expanded optical signal;
a motor arm to move the patterned retarder in and out of an optical path of the optical signal in at least one of an x-, y-, or z-plane to improve the polarization scrambling effect of the patterned retarder;
a beam reducer to reduce the scrambled expanded optical signal from the patterned retarder into a scrambled optical signal; and
an optical fiber output to transmit the scrambled optical signal from the beam reducer to a downstream optical component.

2. The polarization scrambler of claim 1 , wherein each of the optical fiber input and the optical fiber output comprises an array of N×X optical fibers, where N and X are integers.

3. The polarization scrambler of claim 1 , wherein each of the beam expander and the beam reducer comprises one of a collimator, a gradient-index (GRIN) lens, or a bulk lens.

4. The polarization scrambler of claim 1 , wherein the patterned retarder is formed from one of a textured material, a polymer, a birefringent material, or spatial-light-modulation (SLM) based material.

5. The polarization scrambler of claim 4 , wherein the birefringent material comprises one of a liquid crystal, a dielectric thin film, or a phase controlled element.

6. The polarization scrambler of claim 1 , wherein the plurality of patterns in the patterned retarder are arranged in a randomized pattern to randomly divide the expanded optical signal into smaller parts and cause the smaller parts of the expanded optical signal to encounter the different amounts of birefringence to produce different states of polarization that results in the polarization scrambling effect.

7. The polarization scrambler of claim 6 , wherein the randomized pattern in the patterned retarder comprises one of a pixelated pattern, a radial pattern, a wave or zigzag pattern, a line or linear pattern, a checkered pattern, a textured pattern, a scaled pattern, or a gradient pattern.

8. The polarization scrambler of claim 1 , wherein the motor arm is to vibrate or oscillate the patterned retarder to further improve the polarization scrambling effect.

9. A polarization scrambler, comprising:
an optical fiber input to transmit an optical signal;
a beam expander to expand the optical signal from the optical fiber input into an expanded optical signal, wherein the beam expander includes a patterned retarder to create a scrambled expanded optical signal, wherein:
the patterned retarder includes a plurality of different patterns that cause different parts of the expanded optical signal to encounter different amounts of birefringence to produce a polarization scrambling effect on the expanded optical signal that results in the scrambled expanded optical signal;
the patterned retarder further includes a motor arm to move the patterned retarder in and out of an optical path of the optical signal in at least one of an x-, y-, or z-plane to improve the polarization scrambling effect of the patterned retarder;

a beam reducer to reduce the scrambled expanded optical signal from the patterned retarder to create a scrambled optical signal; and
an optical fiber output to transmit the scrambled optical signal to a downstream optical component.

10. The polarization scrambler of claim 9 , wherein each of the optical fiber input and the optical fiber output comprises an array of N×X optical fibers, where N and X are integers.

11. The polarization scrambler of claim 9 , wherein each of the beam expander and the beam reducer comprises one of a collimator, a gradient-index (GRIN) lens, or a bulk lens.

12. The polarization scrambler of claim 9 , wherein the patterned retarder is formed from one of a textured material, a polymer, a birefringent material, or spatial-light-modulation (SLM) based material.

13. The polarization scrambler of claim 12 , wherein the birefringent material comprises one of a liquid crystal, a dielectric thin film, or a phase controlled element.

14. The polarization scrambler of claim 9 , wherein the plurality of patterns in the patterned retarder are arranged in a randomized pattern to randomly divide the expanded optical signal into smaller parts and cause the smaller parts of the expanded optical signal to encounter the different amounts of birefringence to produce different states of polarization that results in the polarization scrambling effect.

15. The polarization scrambler of claim 14 , wherein the randomized pattern in the patterned retarder comprises one of a pixelated pattern, a radial pattern, a wave or zigzag pattern, a line or linear pattern, a checkered pattern, a textured pattern, a scaled pattern, or a gradient pattern.

16. The polarization scrambler of claim 9 , wherein the motor arm is to vibrate or oscillate the patterned retarder to further improve the polarization scrambling effect.

17. A method comprising:
providing an optical fiber input to transmit an optical signal;
providing a beam expander to expand the optical signal from the optical fiber input into an expanded optical signal;
providing a patterned retarder to receive the expanded optical signal from the beam expander and including a plurality of different patterns to cause different parts of the expanded optical signal from the beam expander to encounter different amounts of birefringence to produce a polarization scrambling effect on the expanded optical signal to create a scrambled expanded optical signal;
providing a motor arm to move the patterned retarder in and out of an optical path of the optical signal in at least one of an x-, y-, or z-plane to improve the polarization scrambling effect of the patterned retarder;
providing a beam reducer to reduce the scrambled expanded optical signal from the patterned retarder into a scrambled optical signal; and
providing an optical fiber output to transmit the scrambled optical signal from the beam reducer to a downstream optical component.

18. The method of claim 17 , wherein the plurality of patterns in the patterned retarder are arranged in a randomized pattern to randomly divide the expanded optical signal into smaller parts and cause the smaller parts of the expanded optical signal to encounter the different amounts of birefringence to produce different states of polarization that results in the polarization scrambling effect.

19. The method of claim 18 , wherein the randomized pattern in the patterned retarder comprises one of a pixelated pattern, a radial pattern, a wave or zigzag pattern, a line or linear pattern, a checkered pattern, a textured pattern, a scaled pattern, or a gradient pattern.

20. The method of claim 17 , wherein the motor arm is to vibrate or oscillate the patterned retarder to further improve the polarization scrambling effect.

Assignees

• Viavi Solutions Inc

Inventors

• Philipson Joshua
• Wagner Christopher Russell
• Fernandes Luis Andre Neves Paiva

Classifications

• G02B3/0087 Primary

  with index gradient · CPC title

• G02F1/0136 Primary

  for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence) · CPC title

• G02B6/2786

  Reducing the polarisation degree, i.e. depolarisers, scramblers, unpolarised output · CPC title

• G02B6/2706

  as bulk elements, i.e. free space arrangements external to a light guide, e.g. polarising beam splitters · CPC title

• G02B27/286

  for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34) · CPC title