Systems and methods for photonic polarization rotators

Patent metadata

Field	Value
Publication number	US-10209448-B2
Application number	US-201615246925-A
Country	US
Kind code	B2
Filing date	Aug 25, 2016
Priority date	Jun 8, 2011
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

An integrated non-reciprocal polarization rotator comprises a substrate, a Faraday crystal, a first waveguide, and a second waveguide. The substrate has a recess extending to a predetermined depth. The Faraday crystal is mounted in the recess and optically coupled with the first waveguide and the second waveguide.

First claim

What is claimed is:

1. A photonic device comprising:
a substrate having a support surface and a device surface opposing the support surface, thereby defining a substrate thickness, wherein the substrate includes a fill region;
a Faraday crystal mounted in the fill region and having a first facet and a second facet opposing the first facet;
a first waveguide integrated on the substrate and optically coupled with the first facet of the Faraday crystal;
an index matching region disposed between the first waveguide and the first facet of the Faraday crystal; and
a second waveguide integrated on the substrate and optically coupled with the second facet of the Faraday crystal, wherein:
the Faraday crystal is a first Faraday crystal;
the fill region is a first fill region; and
the photonic device further comprises:
a second fill region in the substrate;
a second Faraday crystal mounted in the second fill region, the second Faraday crystal having a first facet and a second facet opposing the first facet;
a third waveguide integrated on the substrate and coupled with the first facet of the second Faraday crystal;
a fourth waveguide integrated on the substrate and coupled with the second facet of the second Faraday crystal;
a first beam splitter integrated on the substrate; and
a second beam splitter integrated on the substrate;

the first waveguide and the third waveguide are coupled with the first beam splitter; and
the second waveguide and the fourth waveguide are coupled with the second beam splitter.

2. The photonic device of claim 1 , wherein the index matching region is a first index matching region and the photonic device further comprises a second index matching region disposed between the second waveguide and the second facet of the Faraday crystal.

3. The photonic device of claim 1 wherein the Faraday crystal is permanently polled.

4. The photonic device of claim 3 wherein the Faraday crystal comprises at least one of bismuth europium holmium gallium iron garnet or bismuth yttrium iron garnet.

5. The photonic device of claim 1 wherein the Faraday crystal comprises yttrium iron garnet or bismuth-doped iron garnet.

6. The photonic device of claim 5 further comprising a magnet.

7. The photonic device of claim 1 wherein the substrate comprises silicon.

8. The photonic device of claim 7 further comprising an insulating layer disposed between the substrate and the first waveguide; and between the substrate and the second waveguide.

9. The photonic device of claim 8 further comprising an amorphous silicon layer disposed between the insulating layer and the Faraday crystal.

10. The photonic device of claim 1 , wherein the first beam splitter, the second beam splitter, or both the first beam splitter and the second beam splitter are polarizing beam splitters.

11. The photonic device of claim 1 , the photonic device further comprising a reciprocal polarization rotator, wherein:
the reciprocal polarization rotator is between the first waveguide and the first beam splitter; and
the reciprocal polarization rotator is integrated on the substrate.

12. The photonic device of claim 1 , wherein:
the first beam splitter is further coupled with a fifth waveguide;
the fifth waveguide is integrated on the substrate; and
the fifth waveguide is an input port.

13. The photonic device of claim 1 , the photonic device further comprising:
a first reciprocal polarization rotator, wherein:
the first reciprocal polarization rotator is between the first waveguide and the first beam splitter; and
the first reciprocal polarization rotator is integrated on the substrate; and

a second reciprocal polarization rotator, wherein:
the second reciprocal polarization rotator is between the third waveguide and the first beam splitter; and
the second reciprocal polarization rotator is integrated on the substrate.

14. The photonic device of claim 13 , wherein:
the first reciprocal polarization rotator, the first waveguide, the first Faraday crystal, and the second waveguide are on a first optical path between the first beam splitter and the second beam splitter; and
the second reciprocal polarization rotator, the third waveguide, the second Faraday crystal, and the fourth waveguide are on a second optical path between the first beam splitter and the second beam splitter.

Assignees

• Skorpios Tech Inc

Inventors

• Dallesasse John
• Krasulick Stephen B

Classifications

• G02B6/26

  Optical coupling means (G02B6/36, G02B6/42 take precedence) · CPC title

• G02B2006/12061

  Silicon · CPC title

• G02B5/3058 Primary

  comprising electrically conductive elements, e.g. wire grids, conductive particles · CPC title

• G02B6/105

  having optical polarisation effects · CPC title

• G02F1/093

  used as non-reciprocal devices, e.g. optical isolators, circulators (G02F1/0955 takes precedence) · CPC title