Patent ID: 8538221

Claim:
An apparatus comprising: a first semiconductor slab including a first lateral boundary for an optical mode, the first semiconductor slab comprising a silicon material; a second semiconductor slab disposed above and the first lateral boundary included in the first semiconductor slab to asymmetrically overlap, the second semiconductor slab comprising a III-V material and including an active layer extending to an exterior edge of the second semiconductor slab, the exterior edge to form a second lateral boundary for the optical mode, the second lateral boundary disposed above and to a side of the first lateral boundary; a first and a second electrical contact coupled to the second semiconductor slab, one on each lateral side of the second lateral boundary; and an optical waveguide region included in the overlap of the first semiconductor slab and the second semiconductor slab, the optical waveguide region formed by the first and second lateral optical mode boundaries, wherein real and imaginary portions of a refractive index of optical waveguide region changes based on an electrical field generated by an electrical difference applied between the first and second electrical contacts.