Abstract: A mode converter including a silicon waveguide core deposited over a first silicon dioxide cladding layer. The silicon waveguide core is formed such that a first end of the silicon waveguide core has a larger cross-sectional area than a second end of the silicon waveguide core. The silicon waveguide core may include a vertical taper and/or a lateral taper.

Abstract: An apparatus for optical coupling between optical fibers and semiconductor waveguides and method of use thereof. The optical coupler comprises a tapered semiconductor structure having a cross section defined in a plane substantially perpendicular to a direction of propagation of light, which cross section has a dimension accurate to approximately 50 nanometer tolerance. The coupler has an optical index of refraction. The coupler has adjacent thereto material having an optical index less than that of the semiconductor, the adjacent material confining light within the semiconductor structure. In an exemplary embodiment, an optical communication device has two optical couplers disposed one at each end of a semiconductor waveguide to convey an optical communication from a source at one end to receiver at the other. In a further exemplary embodiment, a plurality of optical communication devices are disposed on a single semiconductor substrate.