Patent ID: 8467632

Claim:
An electro-absorption modulator, comprising: a substrate; an optical waveguide, disposed on the substrate, having two portions separated by a gap; a semiconductor layer, disposed on the substrate and substantially filling the gap, wherein the semiconductor layer is coupled to the two portions of the optical waveguide, wherein the semiconductor layer has approximately a same width as the two portions and has approximately a same height as the two portions, and wherein the semiconductor layer has a first edge and a second edge at a periphery along the width of the semiconductor layer; a first intervening layer disposed on the substrate distal from a midline of the semiconductor layer and coupled to the first edge, and a second intervening layer disposed on the substrate distal from the midline of the semiconductor layer and coupled to the second edge, wherein the first intervening layer and the second intervening layer include a material; and a first electrode coupled to the first intervening layer further distal from the midline than the first edge, and a second electrode coupled to the second intervening layer further distal from the midline than the second edge, wherein the material has a lower index of refraction than the semiconductor layer, and a lower optical absorption than the first and second electrodes.