Optical device for phase shifting an optical signal

An electronic system, comprising:

• a processing resource;
• a storage medium communicatively coupled to the processing resource;
• and
• a photonic chip communicatively coupled to the processing resource and comprising an optical device, wherein the optical device comprises:
• an optical waveguide comprising a first semiconductor material region and a second semiconductor material region formed adjacent to each other and defining a junction therebetween, wherein the junction is a PN junction formed at boundaries of the first semiconductor material region and the second semiconductor material region that contact each other;
• an insulating layer formed on top of the optical waveguide;
• and
• a III-V semiconductor layer formed on top of the insulating layer causing an optical mode of an optical signal passing through the optical waveguide to overlap with the first semiconductor material region, the second semiconductor material region, the insulating layer, and the III-V semiconductor layer thereby resulting in a phase shift in the optical signal passing through the optical waveguide.

A method for operating an optical device comprising:

• passing an optical signal through an optical waveguide of the optical device, wherein the optical waveguide comprises a first semiconductor material region and a second semiconductor material region defining a junction therebetween, an insulating layer formed on top of the optical waveguide, and a III-V semiconductor layer formed on top of an insulating layer, wherein the first semiconductor material region, the insulating layer, and the III-V semiconductor layer forms a waveguide integrated capacitor, and wherein an optical mode of an optical signal the optical waveguide to overlap with the first semiconductor material region, the second semiconductor material region, the insulating layer, and the III-V semiconductor layer, wherein the junction is a PN junction formed at boundaries of the first semiconductor material region and the second semiconductor material region that contact each other;
• applying a first control voltage across the junction to cause a change in a refractive index of the optical waveguide;
• and
• applying a second control voltage across the waveguide integrated capacitor to cause a change in a refractive index of the waveguide integrated capacitor in a same direction as the change in the refractive index of the optical waveguide.