Patent ID: 8768124

Claim:
An optical waveguide device, comprising: a waveguide core made of a first dielectric material which has a first refractive index; and a waveguide cladding in contact with at least two opposite sides of the waveguide core and structured to have each waveguide cladding part, which is in contact with the waveguide core, made of a dielectric material with a refractive index less than the first refractive index, and form an optical waveguide with the waveguide core to guide light along a waveguide direction of the optical waveguide, wherein the waveguide core comprises a portion that is shaped to include a waveguide slot, which is made of a second dielectric material having a second refractive index less than the first refractive index of the waveguide core and is elongated along the waveguide direction to have a dimension of less than one wavelength of the guided light along a direction perpendicular to the waveguide direction, and wherein the waveguide slot includes at least two opposite sides that are in contact with the waveguide core to form a slot waveguide and a terminal end that is in contact with a part of the waveguide core without a tapered structure between the part of the waveguide core and the slot waveguide to couple light between the slot waveguide and the waveguide core.