Polarization splitter and rotator

Patent metadata

Field	Value
Publication number	US-11048052-B2
Application number	US-201916580824-A
Country	US
Kind code	B2
Filing date	Sep 24, 2019
Priority date	Sep 24, 2019
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

Example polarization splitter and rotator devices are described. In one example, an optical apparatus includes a splitter configured to split a light signal into a first signal having a first polarization and a second signal having a second polarization, a polarization rotator configured to rotate the second polarization of the second signal into a third polarization, and a polarization mode converter configured to convert the third polarization of the second signal into the first polarization. In certain aspects of the embodiments, the splitter can be a curved multi-mode inference (MMI) polarization splitter, and the polarization rotator comprises input and output ports, with the output port being wider than the input port. The polarization mode converter can be an asymmetrical waveguide taper mode converter. The devices described herein can overcome the deficiencies of conventional devices and provide low insertion loss, flat and/or wide wavelength response, high fabrication tolerance, and compact size.

First claim

The invention claimed is:

1. An optical apparatus comprising:
a curved multi-mode interference (MMI) polarization splitter configured to split a light signal into a first signal having a first polarization and a second signal having a second polarization;
a polarization rotator configured to rotate the second polarization of the second signal into a third polarization; and
a polarization mode converter configured to convert the third polarization of the second signal into the first polarization.

2. The optical apparatus of claim 1 , wherein the polarization rotator comprises an input port and an output port, wherein the output port is wider than the input port.

3. The optical apparatus of claim 2 , wherein the input port is at or about 420 nm wide, and the output port is at or about 1000 nm wide.

4. The optical apparatus of claim 1 , wherein the polarization rotator comprises a rib layer and a ridge layer.

5. The optical apparatus of claim 4 , wherein the rib layer is at or about 90 nm thick.

6. The optical apparatus of claim 4 , wherein the ridge layer is at or about 220 nm thick.

7. The optical apparatus of claim 4 , wherein the rib layer is at or about 1000 nm wide.

8. The optical apparatus of claim 1 , wherein the polarization mode converter is an asymmetrical waveguide taper mode converter.

9. The optical apparatus of claim 1 , wherein the first polarization is a zero order transverse-electric (TE) mode polarization and the second polarization is a zero order transverse-magnetic (TM) mode polarization.

10. The optical apparatus of claim 1 , wherein the third polarization is a first order transverse-electric (TE) mode polarization.

11. The optical apparatus of claim 1 , wherein i) the first signal having the first polarization and ii) the second signal having the third polarization converted into the first polarization are output to one or more receivers.

12. A method of light transmission comprising:
splitting, with a curved multi-mode interference (MMI) polarization splitter, a light signal into a first signal having a first polarization and a second signal having a second polarization;
rotating the second polarization of the second signal into a third polarization; and
converting the third polarization of the second signal into the first polarization.

13. The method of claim 12 , wherein the first polarization is a zero order transverse-electric (TE) mode polarization and the second polarization is a zero order transverse-magnetic (TM) mode polarization.

14. The method of claim 12 , wherein the third polarization is a first order transverse-electric (TE) mode polarization.

15. The method of claim 12 , wherein i) the first signal having the first polarization and ii) the second signal having the third polarization converted into the first polarization are output to one or more receivers.

16. An optical apparatus comprising:
a polarization mode converter configured to convert a first polarization of a first light signal into a second polarization;
a polarization rotator configured to rotate the second polarization of the first light signal into a third polarization, wherein the polarization rotator comprises a rib layer and a ridge layer; and
a combiner configured to form a combined light signal by combining the first light signal having a third polarization with a second light signal having the first polarization.

17. The optical apparatus of claim 16 , wherein the combined light signal is input into one or more optical transmission fibers.

18. The optical apparatus of claim 16 , wherein the first light signal and the second light signal are generated by a laser light source.

19. An optical apparatus comprising:
a splitter configured to split a light signal into a first signal having a first polarization and a second signal having a second polarization;
a polarization rotator configured to rotate the second polarization of the second signal into a third polarization, wherein the polarization rotator comprises an input port and an output port, wherein the input port is at or about 420 nm wide, and the output port is at or about 1000 nm wide; and
a polarization mode converter configured to convert the third polarization of the second signal into the first polarization.

20. An optical apparatus comprising:
a splitter configured to split a light signal into a first signal having a first polarization and a second signal having a second polarization;
a polarization rotator configured to rotate the second polarization of the second signal into a third polarization, wherein the polarization rotator comprises a rib layer and a ridge layer; and
a polarization mode converter configured to convert the third polarization of the second signal into the first polarization.

Assignees

• Macom Tech Solutions Holdings Inc

Inventors

• Li Yunchu
• Griffith Austin G
• Grzybowski Rich R

Classifications

• G02B6/2726

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

• G02B6/2813

  based on multimode interference effect, i.e. self-imaging · CPC title

• G02B6/126 Primary

  using polarisation effects {(G02B6/1226 takes precedence)} · CPC title

• G02B6/2773

  Polarisation splitting or combining · CPC title

• G02B2006/12116

  Polariser; Birefringent · CPC title