Optical modulator with plasmon based coupling

Patent metadata

Field	Value
Publication number	US-9823498-B2
Application number	US-201414908228-A
Country	US
Kind code	B2
Filing date	Jun 16, 2014
Priority date	Jul 30, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A device comprising a metal layer on a crystalline silicon substrate, and a waveguide that has a refractive index greater than that of the crystalline silicon, wherein the waveguide is arranged to couple light to a surface plasmon mode at an interface between the silicon substrate and the metal layer when a waveguide mode is phase matched to the surface plasmon mode.

First claim

The invention claimed is:

1. An electro-optic device, comprising:
a metal layer on a crystalline silicon substrate;
a waveguide that has a refractive index greater than that of the crystalline silicon substrate, wherein the waveguide is arranged to couple light to a surface plasmon mode at an interface between the crystalline silicon substrate and the metal layer when a waveguide mode is phase matched to the surface plasmon mode; and
a modulator for modulating the refractive index of the crystalline silicon substrate to change a phase matching condition between the surface plasmon mode and the waveguide mode to modulate light carried by the waveguide.

2. The electro-optic device as claimed in claim 1 , further comprising a dielectric layer between the metal layer and the waveguide.

3. The electro-optic device as claimed in claim 2 , wherein the modulator is operable to accumulate or deplete the carrier density in the crystalline silicon substrate.

4. The electro-optic device as claimed in claim 2 , wherein the modulator comprises an electrical device formed in or on the crystalline silicon substrate.

5. The electro-optic device as claimed in claim 4 , wherein the electrical device comprises a pin junction.

6. The electro-optic device as claimed in claim 4 , wherein the electrical device comprises a Schottky junction at the metal-silicon substrate interface.

7. The electro-optic device as claimed in claim 1 , wherein a thin oxide layer is provided between the crystalline silicon substrate and the metal.

8. The electro-optic device as claimed in claim 1 , wherein the waveguide comprises amorphous silicon or Silicon Germanium or Germanium.

9. The electro-optic device as claimed in claim 1 , wherein the waveguide is created by ion-implantation.

10. The electro-optic device as claimed in claim 1 , wherein the waveguide is an amorphous silicon waveguide created by ion-implantation.

11. An electrical circuit comprising at least one optical interconnect that includes at least one electro-optic device as claimed in claim 1 .

Assignees

• Univ Court Univ St Andrews

Inventors

• Whelan-Curtin William
• Debnath Kapil

Classifications

• G02F2001/0156

  Physics · mapped topic

• G02F2202/105

  single crystal Si · CPC title

• G02F2203/10

  plasmon · CPC title

• G02F1/025 Primary

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

• G02F1/0156

  using free carrier absorption · CPC title