Polarization scrambler using a retardance element

Patent metadata

Field	Value
Publication number	US-11526035-B2
Application number	US-201916436481-A
Country	US
Kind code	B2
Filing date	Jun 10, 2019
Priority date	Jun 10, 2019
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

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 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 receive and expand the optical signal from the optical fiber input to create an expanded optical signal;
a patterned retarder to cause a polarization scrambling effect on the expanded optical signal to create a scrambled expanded optical signal, wherein:
the patterned retarder comprises a randomized pattern to cause smaller parts of the expanded optical signal to encounter different amounts of birefringence to produce different states of polarization (SOP) that results in the polarization scrambling effect, and
the randomized pattern comprises at least 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;

a motor arm to move the patterned retarder in and out of an optical path of the optical signal and to move the patterned retarder in at least one of an x-, y-, or z-plane to improve the polarization scrambling effect;
a beam reducer to receive and reduce the scrambled expanded optical signal from the patterned retarder to create a scrambled optical signal; and
an optical fiber output to receive and transmit the scrambled optical signal to at least one 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 at least one of a collimator, a gradient-index (GRIN) lens, or a bulk lens.

4. The polarization scrambler of claim 1 , wherein the patterned retarder comprises at least 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 at least one of a liquid crystal, a dielectric thin film, or a phase controlled element.

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

7. A polarization scrambler, comprising:
an optical fiber input to transmit an optical signal;
a beam expander to receive and expand the optical signal from the optical fiber input to create an expanded optical signal, wherein the beam expander comprises a patterned retarder to create a scrambled expanded optical signal, wherein:
the patterned retarder comprises a randomized pattern to cause smaller parts of the expanded optical signal to encounter different amounts of birefringence to produce different states of polarization (SOP) that results in the polarization scrambling effect,
the randomized pattern comprises at least 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, and
the patterned retarder comprises a motor arm to move the patterned retarder in at least one of an x-, y-, or z-plane to improve the polarization scrambling effect, the motor arm to also move the patterned retarder in and out of an optical path of the optical signal;

a beam reducer to receive the scrambled expanded optical signal from the patterned retarder and reduce the scrambled expanded optical signal to a scrambled optical signal; and
an optical fiber output to receive the scrambled optical signal.

8. The polarization scrambler of claim 7 , 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.

9. The polarization scrambler of claim 7 , wherein each of the beam expander and the beam reducer comprises at least one of a collimator, a gradient-index (GRIN) lens, or a bulk lens.

10. The polarization scrambler of claim 7 , wherein the patterned retarder is a thin film coating that comprises at least one of a textured material, a polymer, a birefringent material, or spatial-light-modulation (SLM) based material.

11. The system of claim 10 , wherein the birefringent material comprises at least one of a liquid crystal, a dielectric thin film, or a phase controlled element.

12. The polarization scrambler of claim 7 , wherein the motor arm to vibrate or oscillate the patterned retarder to further improve the polarization scrambling effect.

13. A method of providing a scrambled optical signal, comprising:
providing an optical fiber input to transmit an optical signal;
providing a beam expander to receive and expand the optical signal from the optical fiber input to create an expanded optical signal;
providing a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal to create a scrambled expanded optical signal, wherein:
the retardance element (RE) comprises a randomized pattern to cause smaller parts of the expanded optical signal to encounter different amounts of birefringence to produce different states of polarization (SOP) that results in the polarization scrambling effect, and
the randomized pattern comprises at least 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;

providing a motor arm to move the patterned retarder in and out of an optical path of the optical signal and to move the patterned retarder in at least one of an x-, y-, or z-plane to improve the polarization scrambling effect;
providing a beam reducer to receive the scrambled expanded optical signal from the retardance element (RE) and reduce the scrambled expanded optical signal to create a scrambled optical signal; and
providing an optical fiber output to receive and transmit the scrambled optical signal to at least one downstream optical component.

14. The method of claim 13 , 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.

15. The method of claim 13 , wherein each of the beam expander and the beam reducer comprises at least one of a collimator, a gradient-index (GRIN) lens, or a bulk lens.

16. The method of claim 13 , wherein the retardance element (RE) comprises at least one of a textured material, a polymer, a birefringent material, or spatial-light-modulation (SLM) based material.

17. The method of claim 16 , wherein the birefringent material comprises at least one of a liquid crystal, a dielectric thin film, or a phase controlled element.

18. The method of claim 13 , wherein the motor arm to vibrate or oscillate the retardance element (RE) to further improve the polarization scrambling effect.

Assignees

• Viavi Solutions Inc

Inventors

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

Classifications

• G02F1/0139

  Polarisation scrambling devices; Depolarisers · 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

• H04B10/2569

  due to polarisation mode dispersion [PMD] · CPC title

• G02B6/2706

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

• H04J14/06

  Polarisation multiplex systems · CPC title