Apparatus and method for a waveguide polarizer comprising a series of bends

Patent metadata

Field	Value
Publication number	US-9690045-B2
Application number	US-201414231429-A
Country	US
Kind code	B2
Filing date	Mar 31, 2014
Priority date	Mar 31, 2014
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

Embodiments are provided for a waveguide polarizer comprising a series of bends. The waveguide polarizer is suitable for used in optical waveguide devices or circuits, where a polarized light is required, such as for single polarization output. The polarizer design is independent of the function of the optical devices. In an embodiment, an optical polarizer comprises an optical waveguide configured to propagate light at a designated polarization mode, and comprising a bend in a same plane of the propagated light. The bend has a geometry configured to contain in the optical waveguide the designated polarization mode of the propagated light and radiate outside the optical waveguide a second polarization mode of the propagated light.

First claim

What is claimed is:

1. An optical receiver comprising:
a first optical waveguide configured to propagate light in a designated polarization mode, and comprising at least a first bend and a second bend in a plane of the propagated light,
wherein the first bend has a geometry configured to contain in the first optical waveguide the designated polarization mode of the propagated light and radiate outside the first optical waveguide a second polarization mode of the propagated light, and wherein the first bend is between 90 degrees and 180 degrees, wherein at least one of the first bend and the second bend has a double serpentine shape.

2. The optical receiver of claim 1 , wherein the second polarization mode is orthogonal to the designated polarization mode.

3. The optical receiver of claim 1 , wherein the designated polarization mode is a transverse electrical (TE) mode, and wherein the second polarization mode is a transverse magnetic (TM) mode.

4. The optical receiver of claim 1 , wherein the geometry of the first bend is one of circular, adiabatic, Bezier curve shaped, and sine curve shaped.

5. The optical receiver of claim 1 , wherein the geometry of the first bend comprises a first adiabatic sine curve coupled to a straight waveguide section, a constant radius turn coupled to the first adiabatic sine curve, and a second adiabatic sine curve coupled to the constant radius turn and to a second straight waveguide section.

6. The optical receiver of claim 1 , wherein the first bend is a 90 degree bend in the first optical waveguide.

7. The optical receiver of claim 1 , wherein the first bend is a 180 degree bend in the first optical waveguide.

8. The optical receiver of claim 1 , wherein the first optical waveguide including the first bend comprises a core of silicon.

9. The optical receiver of claim 8 , wherein the first optical waveguide including the first bend comprises a cladding of silicon oxide surrounding the core.

10. The optical receiver of claim 1 , wherein the first optical waveguide including the first bend is comprised of silicon on an insulator substrate.

11. An optical receiver comprising:
an optical waveguide configured to propagate light at a desired polarization mode; a bent waveguide coupled to the optical waveguide, and configured with a bent geometry to contain in the bent waveguide the desired polarization mode of the propagated light and radiate outside the bent waveguide a second polarization mode of the propagated light;
a polarizing beam splitter (PBS) coupled to the optical waveguide via the bent waveguide, wherein the bent waveguide is a polarizer for a first light mode from the PBS to the optical waveguide;
a second optical waveguide similar to the optical waveguide coupled to the PBS; and
a second bent waveguide similar to the bent waveguide, wherein the second bent waveguide is positioned between the PBS and the second optical waveguide, and is a polarizer for a second light mode from the PBS to the second optical waveguide.

12. The optical receiver for claim 11 , wherein the desired polarization mode is a transverse electrical (TE) mode, and wherein the bent waveguide has a rectangular cross section profile with a larger width than height.

13. The optical receiver for claim 11 , wherein the desired polarization mode is a transverse magnetic (TM) mode, and wherein the bent waveguide has a rectangular cross section profile with a larger height than width.

14. The optical receiver of claim 11 , wherein the optical waveguide and the bent waveguide are fabricated via a same sequence of lithographic processes using same semiconductor and dielectric materials.

15. The optical receiver of claim 11 , wherein the bent waveguide comprises a series of bends having one of a serpentine shape and a double serpentine shape.

16. The optical receiver of claim 11 , wherein the bent waveguide is surrounded with a light-absorbing material.

17. The optical receiver of claim 16 , wherein the light-absorbing material is one of germanium and doped silicon on a substrate.

18. An optical device comprising:
an optical waveguide configured to propagate light at a desired polarization mode; a bent waveguide coupled to the optical waveguide, and configured with a bent geometry to contain in the bent waveguide the desired polarization mode of the propagated light and radiate outside the bent waveguide a second polarization mode of the propagated light;
a polarization splitter; and
a switch matrix comprising the optical waveguide and coupled to the polarization splitter via the bent waveguide, wherein the bent waveguide is a polarizer for a transverse electrical mode between the polarization splitter and the switch matrix.

19. The optical device of claim 18 , wherein the optical device further comprises a polarization rotator positioned between the bent waveguide and the polarization splitter.

20. An optical device comprising:
a first optical waveguide configured to propagate light at a first polarization mode; and
a first bent waveguide having a bent geometry and coupled to the first optical waveguide, the first bent waveguide configured to contain in the first polarization mode of the propagated light inside the first bent waveguide, and to radiate outside the first bent waveguide a second polarization mode of the propagated light, wherein the bent geometry comprises a first adiabatic sine curve coupled to a straight waveguide section, a constant radius turn coupled to the first adiabatic sine curve, and a second adiabatic sine curve coupled in between the constant radius turn and a second straight waveguide section.

21. The optical device of claim 20 , further comprising:
a polarizing beam splitter (PBS) coupled to the first optical waveguide via the first bent waveguide, wherein the first bent waveguide is a polarizer for a first light mode from the PBS to the first optical waveguide;
a second optical waveguide having a cross-section similar to a cross-section of the first optical waveguide and rotated by 90 degrees with respect to the cross-section of the first optical waveguide, wherein the second optical waveguide is coupled to the PBS; and
a second bent waveguide having a cross-section similar to a cross-section of the first bent waveguide and rotated by 90 degrees with respect to the cross-section of the first bent waveguide, wherein the second bent waveguide is positioned between the PBS and the rotated second optical waveguide, and is a polarizer for a second light mode from the PBS to the second optical waveguide.

22. The optical receiver of claim 1 , further comprises:
a polarizing beam splitter (PBS) coupled to the first optical waveguide via the first bend, wherein the first bend is a polarizer for a first light mode from the PBS to the first optical waveguide;
a second optical waveguide similar to the first optical waveguide and having a cross-section rotated by 90 degrees with respect to a cross-section of the first optical waveguide, wherein the second optical waveguide is coupled to the PBS; and
a second bend similar to the first bend and having a cross-section rotated by 90 degrees with respect to a cross-section of the first bend, wherein the second bend is positioned between the PBS and the second optical waveguide, and is a polarizer for a second light mode from the PBS to the second optical waveguide.

Assignees

• Huawei Tech Co Ltd

Inventors

• Goodwill Dominic John
• Jiang Jia

Classifications

• G02B6/13

  Integrated optical circuits characterised by the manufacturing method · CPC title

• G02B6/126 Primary

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

• H04B10/60

  Receivers · CPC title

• G02B6/125

  Bends, branchings or intersections · CPC title

• G02B6/27

  with polarisation selective and adjusting means · CPC title