Electro-optic device with semiconductor junction area and related methods

Patent metadata

Field	Value
Publication number	US-11269140-B2
Application number	US-201816185654-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Jun 30, 2015
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

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

What 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, the first semiconductor layer comprising a first base and a first plurality of ridges extending away from a first major surface of the first base; and
a second semiconductor layer of a second conductivity type different from the first conductivity type, a first major surface of the second semiconductor layer physically contacting a second major surface of the first base opposite the first major surface of the first base, wherein the first major surface of the second semiconductor layer and the second major surface of the first base define a semiconductor junction area; and

a circuit coupled to the optical grating coupler and configured to provide a bias voltage to the semiconductor junction area, the bias voltage dynamically varying as a function of a temperature of the optical grating coupler and changing at least one optical characteristic of the optical grating coupler.

2. The electro-optic device of claim 1 , wherein the first plurality of ridges have non-uniform widths.

3. The electro-optic device of claim 2 , wherein said first base comprises a first end and a second end, and wherein a width of the first plurality of ridges progressively increases from the first end to the second end.

4. The electro-optic device of claim 1 , wherein the first plurality of ridges have uniform widths.

5. The electro-optic device of claim 1 , wherein the first plurality of ridges extends vertically from the first major surface of the first base to define a plurality of recesses between adjacent ridges of the first plurality of ridges.

6. The electro-optic device of claim 1 , wherein the first plurality of ridges is curved in a top-down view of the electro-optic device.

7. The electro-optic device of claim 1 , wherein the photonic chip comprises a first terminal and a second terminal respectively coupled to the first base and the second semiconductor layer.

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

9. The electro-optic device of claim 1 , further comprising an optical element disposed over the optical grating coupler and defining an optical path above the optical grating coupler.

10. The electro-optic device of claim 9 , wherein the optical element comprises an optical fiber.

11. The electro-optic device of claim 1 , wherein the circuit is configured to bias the semiconductor junction area and change at least one optical characteristic of the optical grating coupler by adding current flow to the semiconductor junction area or by adding a depletion region to the semiconductor junction area.

12. The electro-optic device of claim 1 , wherein a thickness of the first plurality of ridges is non-uniform, and wherein the circuit is further configured to provide a constant voltage to the optical grating coupler to compensate for a non-uniformity of the thickness of the first plurality of ridges.

13. The electro-optic device of claim 1 , wherein the circuit is configured to vary the bias voltage dynamically as the function of the temperature of the optical grating coupler so as to maintain a peak wavelength of the optical grating coupler at a predetermined level.

14. The electro-optic device of claim 1 , further comprising a substrate layer and an insulating layer disposed over the substrate layer, wherein a second major surface of the second semiconductor layer, opposite the first major surface of the second semiconductor layer, physically contacts the insulating layer.

15. An electro-optic system, comprising:
a first optical grating coupler;
a second optical grating coupler; and
an optical waveguide coupled between an output of the first optical grating coupler and an input of the second optical grating coupler, wherein the first optical grating coupler comprises:
a first semiconductor layer of a first conductivity type, the first semiconductor layer comprising a first base and a first plurality of ridges extending away from a first major surface of the first base; and
a second semiconductor layer of a second conductivity type different from the first conductivity type, a first major surface of the second semiconductor layer physically contacting a second major surface of the first base opposite the first major surface of the first base, wherein the first major surface of the second semiconductor layer and the second major surface of the first base define a semiconductor junction area; and

a circuit coupled to the first optical grating coupler and configured to provide a bias voltage to the semiconductor junction area, the bias voltage dynamically varying as a function of a temperature of the first optical grating coupler and changing at least one optical characteristic of the first optical grating coupler.

16. The electro-optic system of claim 15 , wherein the first optical grating coupler is configured to receive an optical source signal and an electrical command signal from the circuit and to modulate a phase of the optical source signal based on the electrical command signal to produce a phase-shifted optical source signal.

17. The electro-optic system of claim 16 , wherein the second optical grating coupler is configured to receive the phase-shifted optical source signal and to modulate the phase-shifted optical source signal to produce a modulated optical source signal at an output of the second optical grating coupler.

18. The electro-optic system of claim 15 , wherein the first plurality of ridges have non-uniform widths.

19. The electro-optic system of claim 18 , wherein said first base comprises a first end and a second end, and wherein a width of the first plurality of ridges progressively increases from the first end to the second end.

20. The electro-optic system of claim 15 , wherein the first plurality of ridges has uniform widths.

21. The electro-optic system of claim 15 , wherein the second optical grating coupler comprises:
a first semiconductor layer of a first conductivity type, the first semiconductor layer comprising a first base and a first plurality of ridges extending away from a first major surface of the first base; and
a second semiconductor layer of a second conductivity type different from the first conductivity type, a first major surface of the second semiconductor layer physically contacting a second major surface of the first base opposite the first major surface of the first base, wherein the first major surface of the second semiconductor layer and the second major surface of the first base define a semiconductor junction area.

22. 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, the first semiconductor layer comprising a first base and a first plurality of ridges extending away from a first major surface of the first base; and
a second semiconductor layer of a second conductivity type different from the first conductivity type, a first major surface of the second semiconductor layer physically contacting a second major surface of the first base opposite the first major surface of the first base, wherein the fir

Assignees

• St Microelectronics Sa
• St Microelectronics Crolles 2 Sas

Inventors

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

Classifications

• G02B6/29395

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

• G02F1/025

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

• G02B6/124 Primary

  Geodesic lenses or integrated gratings · CPC title

• G02B6/30

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

• G02F2201/302

  grating coupler · CPC title