Optical coupler

An optical coupler comprising:

• a first optical waveguide base layer and a second optical waveguide base layer, wherein the first optical waveguide base layer comprises a first-type doping and the second optical waveguide base layer comprises a second-type doping;
• an insulating layer disposed over at least a portion of both the first optical waveguide base layer and the second optical waveguide base layer;
• a semiconductor material layer disposed over the insulating layer and comprising a first portion disposed over the first optical waveguide base layer and a second portion disposed over the second optical waveguide base layer, wherein the first portion comprises the second-type doping and the second portion comprises the first type-doping, wherein overlapping portions of the first optical waveguide base layer, the insulating layer, and the semiconductor material layer form a first optical waveguide, and wherein overlapping portions of the second optical waveguide base layer, the insulating layer, and the semiconductor material layer form a second optical waveguide;
• and
• a plurality of metal contacts disposed in contact with one or more of the semiconductor material layer, the first optical waveguide base layer, and the second optical waveguide base layer to receive one or more biasing voltages to operate the first optical waveguide in an accumulation mode and operate the second optical waveguide in a depletion mode.

A method for operating an optical coupler, comprising:

• operating a first optical waveguide in an accumulation mode;
• and
• operating a second optical waveguide in a depletion mode, wherein the optical coupler comprises:
• a first optical waveguide base layer comprising a first-type doping, a second optical waveguide base layer comprising a second-type doping, an insulating layer disposed over at least a portion of both the first optical waveguide base layer and the second optical waveguide base layer, a semiconductor material layer disposed over the insulating layer and comprising a first portion with the second-type doping disposed over the first optical waveguide base layer and a second portion with the first-type doping disposed over the second optical waveguide base layer, and a plurality of metal contacts disposed in contact with the semiconductor material layer, the first optical waveguide base layer and the second optical waveguide base layer, wherein overlapping portions of the first optical waveguide base layer, the insulating layer, and the semiconductor material layer form the first optical waveguide, and wherein overlapping portions of the second optical waveguide base layer, the insulating layer, and the semiconductor material layer form the second optical waveguide, and
• wherein operating the first optical waveguide in the accumulation mode and operating the second optical waveguide in the depletion mode comprises applying biasing voltages on the plurality of metal contacts.