Spiral optical waveguide termination

Patent metadata

Field	Value
Publication number	US-10527792-B2
Application number	US-201615142434-A
Country	US
Kind code	B2
Filing date	Apr 29, 2016
Priority date	Apr 29, 2016
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

An optical waveguide termination comprising a light-receiving inlet for receiving light to be terminated, a curved section extending from the inlet and having a continuously decreasing radius of curvature, and a light-terminating tip at an end of the curved section. The curved section may define a spiral waveguide, for example a logarithmic spiral, having a waveguide width that continuously decreases from the inlet to the tip.

First claim

The invention claimed is:

1. An optical waveguide termination comprising:
a light-receiving inlet for receiving light to be terminated;
a curved section of a nanotaper waveguide extending from the inlet and having a continuously decreasing radius of curvature; and
a light-terminating tip at an end of the curved section;
wherein the curved section defines a spiral and has a waveguide width that continuously decreases from the inlet to the tip.

2. The optical waveguide termination of claim 1 wherein the optical waveguide termination is a silicon waveguide.

3. The optical waveguide termination of claim 2 wherein the silicon waveguide is partially etched.

4. The optical waveguide termination of claim 1 further comprising a doped region.

5. The optical waveguide termination of claim 1 wherein the tip comprises a facet angled with respect to an inlet face of the inlet-receiving inlet to further suppress back-reflection.

6. The optical waveguide termination of claim 1 wherein the spiral is a logarithmic spiral.

7. The optical waveguide termination of claim 6 wherein the logarithmic spiral comprises a radius of curvature that varies on a log scale from 5 μm to 1 μm over a length of 30 μm.

8. The optical waveguide termination of claim 1 wherein the light-receiving inlet has an inlet width of 500 nm and the light-terminating tip has a tip width of 200 nm.

9. A photonic platform comprising:
a substrate;
a buried oxide layer on the substrate;
an optical circuit formed in an active silicon layer; and
an optical waveguide termination formed in the active silicon layer and connected to the optical circuit, the optical waveguide termination comprising:
a light-receiving inlet for receiving light to be terminated;
a curved section of a nanotaper waveguide extending from the inlet and having a continuously decreasing radius of curvature; and
a light-terminating tip at an end of the curved section;
wherein the curved section has a waveguide width that continuously decreases from the inlet to the tip.

10. The photonic platform of claim 9 wherein the optical waveguide is a partially etched silicon waveguide.

11. The photonic platform of claim 9 further comprising a doped region.

12. The photonic platform of claim 9 wherein the tip comprises a facet angled with respect to an inlet face of the inlet-receiving inlet to further suppress back-reflection.

13. The photonic platform of claim 9 wherein the curved section defines a spiral.

14. The photonic platform of claim 13 wherein the spiral is a logarithmic spiral.

15. A method of terminating light, the method comprising:
receiving light to be terminated at a light-receiving inlet of an optical waveguide termination;
propagating the light through a curved section of a nanotaper waveguide extending from the inlet and having a continuously decreasing radius of curvature; and
terminating the light at a light-terminating tip at an end of the curved section;
wherein propagating the light through the curved section comprises propagating the light through a spiral waveguide having a waveguide width that continuously decreases from the inlet to the tip.

16. The method of claim 15 further comprising absorbing the light using a doped region.

Assignees

• Huawei Tech Co Ltd

Inventors

• Dumais Patrick

Classifications

• G02B6/243 Primary

  as light absorbers · CPC title

• G02B6/1347

  using ion implantation (ion implantation in glass C03C23/0055; ion implantation in general C23C) · CPC title

• G02B6/122

  Basic optical elements, e.g. light-guiding paths · CPC title

• G02B6/136

  by etching · CPC title

• G02B6/134

  by substitution by dopant atoms · CPC title