Method and system for eliminating polarization dependence for 45 degree incidence MUX/DEMUX designs

Patent metadata

Field	Value
Publication number	US-11018796-B2
Application number	US-201916694318-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Oct 12, 2017
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

Methods and systems for eliminating polarization dependence for 45 degree incidence MUX/DEMUX designs may include an optical transceiver, where the optical transceiver comprises an input optical fiber, a beam splitter, and a plurality of thin film filters arranged above corresponding grating couplers in a photonics die. The transceiver may receive an input optical signal comprising different wavelength signals via the input optical fiber, split the input optical signal into signals of first and polarizations using the beam splitter by separating the signals of the second polarization laterally from the signals of the first polarization, communicate the signals of the first polarization and the second polarization to the plurality of thin film filters, and reflect signals of each of the plurality of different wavelength signals to corresponding grating couplers in the photonics die using the thin film filters.

First claim

What is claimed is:

1. A method for communication, the method comprising:
in an optical transceiver comprising a beam splitter and a plurality of filters arranged above corresponding grating couplers in a photonic die:
receiving an optical signal comprising a plurality of different wavelength signals;
splitting the optical signal into signals of a first polarization and signals of a second polarization using the beam splitter by separating the signals of the second polarization laterally from the signals of the first polarization;
communicating the signals of the first polarization and the second polarization to the plurality of filters;
reflecting, using a first filter of the plurality of filters, the signals of the first polarization to a first corresponding grating coupler of the corresponding grating couplers;
communicating, using the first filter, the signals of the second polarization to a second filter of the plurality of filters; and
reflecting, using the second filter, the signals of the second polarization to a second corresponding grating coupler of the corresponding grating couplers.

2. The method according to claim 1 , comprising communicating optical signals of a plurality of wavelengths out of the photonic die to the filters.

3. The method according to claim 2 , comprising reflecting each of the optical signals from the photonic die to the beam splitter using the filters.

4. The method according to claim 3 , comprising communicating the reflected optical signals from the photonic die to an output fiber of the optical transceiver.

5. The method according to claim 1 , wherein the beam splitter comprises a thin film stack on an angled surface of a first prism, the thin film stack being configured to reflect signals of the second polarization while allowing signals of the first polarization to pass through.

6. The method according to claim 5 , comprising communicating the separated signals of the second polarization to the plurality of filters using a mirror in the beam splitter formed on an angled surface of a second prism adjacent to the first prism.

7. The method of claim 6 , comprising rotating a polarization of the reflected signals of the second polarization using a polarization rotator on the second prism before being communicated to the plurality of filters.

8. The method of claim 1 , comprising separating the signals of the second polarization laterally from the signals of the first polarization using a birefringent material.

9. The method of claim 8 , wherein the birefringent material allows signals of the first polarization to pass directly through to the plurality of filters.

10. The method of claim 9 , comprising rotating polarization of the signals of the first polarization after passing through the birefringent material.

11. A system for communication, the system comprising:
an optical transceiver comprising a beam splitter and a plurality of filters arranged above corresponding grating couplers in a photonic die, the optical transceiver being operable to:
receive an optical signal comprising a plurality of different wavelength signals;
split the optical signal into signals of a first polarization and signals of a second polarization using the beam splitter by separating the signals of the second polarization laterally from the signals of the first polarization;
communicate the signals of the first polarization and the second polarization to the plurality of filters;
reflect, using a first filter of the plurality of filters, the signals of the first polarization to a first corresponding grating coupler of the corresponding grating couplers;
communicate, using the first filter, the signals of the second polarization to a second filter of the plurality of filters; and
reflect, using the second filter, the signals of the second polarization to a second corresponding grating coupler of the corresponding grating couplers.

12. The system according to claim 11 , wherein the optical transceiver is operable to communicate optical signals of a plurality of wavelengths out of the photonic die to the filters.

13. The system according to claim 12 , wherein the optical transceiver is operable to reflect each of the optical signals from the photonic die to the beam splitter using the filters.

14. The system according to claim 13 , wherein the optical transceiver is operable to communicate the reflected optical signals from the photonic die to an output fiber of the optical transceiver.

15. The system according to claim 11 , wherein the beam splitter comprises a thin film stack on an angled surface of a first prism, the thin film stack being configured to reflect signals of the second polarization while allowing signals of the first polarization to pass through.

16. The system according to claim 15 , wherein the optical transceiver is operable to communicate the separated signals of the second polarization to the plurality of filters using a mirror in the beam splitter formed on an angled surface of a second prism adjacent to the first prism.

17. The system according to claim 16 , wherein the optical transceiver is operable to rotate a polarization of the reflected signals of the second polarization using a polarization rotator on the second prism before being communicated to the plurality of filters.

18. The system according to claim 11 , wherein the optical transceiver is operable to separate the signals of the second polarization laterally from the signals of the first polarization using a birefringent material which allows signals of the first polarization to pass directly through to the plurality of filters.

19. The system according to claim 11 , wherein the optical transceiver is operable to rotate polarization of the signals of the first polarization after passing through the birefringent material.

20. A system for communication, the system comprising:
an optical transceiver comprising a photonic die and a plurality of filters arranged above corresponding grating couplers in the photonic die, the optical transceiver being operable to:
receive an optical signal comprising a plurality of different wavelength signals;
communicate the optical signal to the plurality of filters;
reflect, using a first filter of the plurality of filters, a first signal of the plurality of different wavelength signals to a first corresponding grating coupler of the corresponding grating couplers;
communicate, using the first filter, a second signal of the plurality of different wavelength signals to a second filter of the plurality of filters; and
reflect, using the second filter, the second signal to a second corresponding grating coupler of the corresponding grating couplers.

Assignees

• Luxtera Llc

Inventors

• Sahni Subal
• Guckenberger John Andrew

Classifications

• G02B6/30

  for use between fibre and thin-film device · CPC title

• H04B10/40

  Transceivers · CPC title

• G02B6/272

  comprising polarisation means for beam splitting and combining · CPC title

• G02B6/2938

  for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM · CPC title

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title