Symmetric coherent optical mixer

Patent metadata

Field	Value
Publication number	US-10731383-B2
Application number	US-201816051965-A
Country	US
Kind code	B2
Filing date	Aug 1, 2018
Priority date	Aug 1, 2018
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

Aspects of a symmetric coherent optical mixer are described. In one example, the coherent optical mixer includes a group of symmetric MMI couplers and a group of symmetric bend waveguides optically coupled between the MMI couplers. The group of symmetric MMI couplers can include an input for a local light reference signal, an input for a modulated light signal, and outputs for detection of data from the modulated light signal. The group of symmetric MMI couplers can include four MMI couplers, each of which comprises a 2×2 MMI coupler of symmetric dimension. The group of symmetric bend waveguides can include a symmetric layout of four 90° bend waveguides optically coupled between the four MMI couplers. The coherent optical mixer, which can be implemented as a Silicon Photonics (SiPh) device, provides better performance as a 90° degree optical hybrid than prior mixer devices due to its symmetric layout.

First claim

The invention claimed is:

1. An optical device, comprising:
a local input multimode interference (MMI) coupler comprising an input for a local light reference signal;
a symmetric quadruple of MMI couplers, the symmetric quadruple of MMI couplers comprising an input for an output of the local input MMI coupler, an input for a modulated light signal, and a plurality of outputs for detection of data from the modulated light signal; and
a symmetric quadruple of bend waveguides optically coupled between the symmetric quadruple of MMI couplers.

2. The optical device of claim 1 , wherein the optical device comprises a symmetric optical coherent mixer device.

3. The optical device of claim 1 , wherein the optical device is integrated using semiconducting materials as a Silicon Photonics (SiPh) device.

4. The optical device of claim 1 , wherein the local input MMI coupler comprises a 1×2 MMI coupler.

5. The optical device of claim 1 , wherein:
the symmetric quadruple of MMI couplers comprises a symmetric layout of four MMI couplers;
a first MMI coupler among the four MMI couplers comprises the input for the output of the local input MMI coupler; and
a second MMI coupler among the four MMI couplers comprises the input for the modulated light signal.

6. The optical device of claim 5 , wherein each of the four MMI couplers comprises a 2×2 MMI coupler of symmetric dimension.

7. The optical device of claim 5 , wherein:
no phase difference is exhibited at outputs of the first MMI coupler; and
a 90° phase difference is exhibited at outputs of the second MMI coupler.

8. The optical device of claim 5 , wherein:
a third MMI coupler among the four MMI couplers comprises an in-phase output for detection of the data from the modulated light signal; and
a fourth MMI coupler among the four MMI couplers comprises a quadrature output for detection of the data from the modulated light signal.

9. The optical device of claim 8 , wherein:
the symmetric quadruple of bend waveguides comprises a symmetric layout of four 90° bend waveguides; and
each waveguide among the four 90° bend waveguides is optically coupled between a respective pair of the four MMI couplers.

10. An optical device, comprising:
a local input multimode interference (MMI) coupler;
a symmetric quadruple of multimode interference (MMI) couplers, the symmetric quadruple of MMI couplers comprising an input optically coupled to an output of the local input MMI coupler, an input for a modulated light signal, and a plurality of outputs for detection of data from the modulated light signal; and
a symmetric quadruple of bend waveguides optically coupled between the symmetric quadruple of MMI couplers.

11. The optical device of claim 10 , wherein the optical device comprises a symmetric optical coherent mixer device.

12. The optical device of claim 10 , wherein:
the symmetric quadruple of MMI couplers comprises a symmetric layout of four MMI couplers;
a first MMI coupler among the four MMI couplers comprises the input optically coupled to an output of the local input MMI coupler; and
a second MMI coupler among the four MMI couplers comprises the input for the modulated light signal.

13. The optical device of claim 12 , wherein each of the four MMI couplers comprises a 2×2 MMI coupler of symmetric dimension.

14. The optical device of claim 12 , wherein:
a third MMI coupler among the four MMI couplers comprises an in-phase output for detection of the data from the modulated light signal; and
a fourth MMI coupler among the four MMI couplers comprises a quadrature output for detection of the data from the modulated light signal.

15. The optical device of claim 14 , wherein:
the symmetric quadruple of bend waveguides comprises a symmetric layout of four 90° bend waveguides; and
each waveguide among the four 90° bend waveguides is optically coupled between a respective pair of the four MMI couplers.

16. A Silicon Photonics (SiPh) optical device, comprising:
a 1×2 multimode interference (MMI) coupler comprising an input for a local light reference signal;
a symmetric quadruple of MMI couplers comprising a pair of inputs optically coupled to a pair of outputs from the 1×2 MMI coupler, an input for a modulated light signal, and a plurality of outputs for detection of data from the modulated light signal; and
symmetric waveguides optically coupled between the symmetric quadruple of MMI couplers.

17. The SiPh optical device of claim 16 , wherein the symmetric quadruple of MMI couplers comprises a symmetric layout of four MMI couplers.

18. The SiPh optical device of claim 17 , wherein each of the four MMI couplers comprises a 2×2 MMI coupler of symmetric dimension.

19. The SiPh optical device of claim 17 , wherein:
no phase difference is exhibited at outputs of a first MMI coupler among the four MMI couplers; and
a 90° phase difference is exhibited at outputs of a second MMI coupler among the four MMI couplers.

20. The SiPh optical device of claim 19 wherein:
a third MMI coupler among the four MMI couplers comprises an in-phase output for detection of the data from the modulated light signal; and
a fourth MMI coupler among the four MMI couplers comprises a quadrature output for detection of the data from the modulated light signal.

Assignees

• Macom Tech Solutions Holdings Inc

Inventors

• Yamazaki Hiroyuki

Classifications

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