Electro-optic device with semiconductor junction area and related methods

Patent metadata

Field	Value
Publication number	US-10126499-B2
Application number	US-201514754994-A
Country	US
Kind code	B2
Filing date	Jun 30, 2015
Priority date	Jun 30, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An electro-optic device may include a photonic chip having an optical grating coupler at a surface. The optical grating coupler may include a first semiconductor layer having a first base and first fingers extending outwardly from the first base. The optical grating coupler may include a second semiconductor layer having a second base and second fingers extending outwardly from the second base and being interdigitated with the first fingers to define semiconductor junction areas, with the first and second fingers having a non-uniform width. The electro-optic device may include a circuit coupled to the optical grating coupler and configured to bias the semiconductor junction areas and change one or more optical characteristics of the optical grating coupler.

First claim

That which is claimed is:

1. An electro-optic device comprising:
a photonic chip having an optical grating coupler at a surface thereof, the optical grating coupler comprising
a first semiconductor layer of a first conductivity type and comprising a first base and a first plurality of fingers extending outwardly therefrom, and
a second semiconductor layer of a second conductivity type comprising a second base and a second plurality of fingers extending outwardly therefrom and being interdigitated and in physical contact with said first plurality of fingers to define a plurality of semiconductor junction areas disposed between contacting sidewalls of the first plurality of fingers and the second plurality of fingers, said first and second pluralities of fingers having a non-uniform width; and

a circuit coupled to said optical grating coupler and configured to apply a first voltage to each of the first plurality of fingers and a second voltage to each of the second plurality of fingers to change at least one optical characteristic of the optical grating coupler.

2. The electro-optic device of claim 1 wherein top surfaces of said first plurality of fingers extends vertically away from a substrate and past top surfaces of said second plurality of fingers to define a plurality of recesses filled with a dielectric material respectively aligned with said second plurality of fingers.

3. The electro-optic device of claim 1 wherein said first base has first and second ends; and wherein said first plurality of fingers progressively increase in width from the first end to the second end.

4. The electro-optic device of claim 1 wherein said first and second pluralities of fingers are curved.

5. The electro-optic device of claim 1 wherein said photonic chip comprises first and second terminals coupled respectively to said first and second bases and configured to respectively receive the first voltage and the second voltage.

6. The electro-optic device of claim 1 wherein the at least one optical characteristic comprises at least one of a peak power wavelength, an optical loss, and a refractive index.

7. The electro-optic device of claim 1 further comprising an optical element defining an optical path above said optical grating coupler.

8. The electro-optic device of claim 7 wherein said optical element comprises an optical fiber.

9. A method of making an electro-optic device comprising:
forming a photonic chip having an optical grating coupler at a surface thereof, the optical grating coupler comprising
a first semiconductor layer of a first conductivity type and comprising a first base and a first plurality of fingers extending outwardly therefrom, and
a second semiconductor layer of a second conductivity type comprising a second base and a second plurality of fingers extending outwardly therefrom and being interdigitated and in physical contact with the first plurality of fingers to define a plurality of semiconductor junction areas between facing surfaces of the first plurality of fingers and the second plurality of fingers, the first and second pluralities of fingers having a non-uniform width; and

coupling a circuit to the optical grating coupler
applying, using the circuit, a first voltage to each of the first plurality of fingers and a second voltage to each of the second plurality of fingers, the applying being configured to bias the plurality of semiconductor junction areas and change at least one optical characteristic of the optical grating coupler.

10. The method of claim 9 wherein the first plurality of fingers extends vertically past the second plurality of fingers to define a plurality of recesses respectively aligned with the second plurality of fingers.

11. The method of claim 9 wherein the first base has first and second ends; and wherein the first plurality of fingers progressively increase in width from the first end to the second end.

12. The method of claim 9 wherein the first and second pluralities of fingers are curved.

13. The method of claim 9 wherein the photonic chip comprises first and second terminals coupled respectively to the first and second bases.

14. The method of claim 9 wherein the at least one optical characteristic comprises at least one of a peak power wavelength, an optical loss, and a refractive index.

15. The method of claim 9 further comprising coupling an optical element to define an optical path above the optical grating coupler.

16. The method of claim 15 wherein the optical element comprises an optical fiber.

Assignees

• St Microelectronics Sa
• St Microelectronics Crolles 2 Sas

Inventors

• Manouvrier Jean-Robert
• Carpentier Jean-Francois
• Lemaitre Patrick

Classifications

• G02B6/30

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

• G02B6/124 Primary

  Geodesic lenses or integrated gratings · CPC title

• G02B6/29395

  configurable, e.g. tunable or reconfigurable (switching G02B6/35) · CPC title

• G02F2201/302

  grating coupler · CPC title

• G02F1/025

  in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) · CPC title