Optical waveguide structures and formation methods

Abstract

A method is provided for forming an optical waveguide structure upon a substrate in accordance with the steps of: (a) forming a layer of base coat material upon the substrate, (b) forming a layer of cladding material having a predetermined refractive index upon the base coat layer, (c) applying a channel waveguide pattern defining structure to the layer of cladding material, (d) applying a patterning agent to transfer the pattern of the channel waveguide pattern defining structure to a predetermined depth or depths into the cladding material layer to define a waveguide trench pattern, (e) removing any remaining residue of channel waveguide pattern defining structure, (f) forming a thick coat layer of waveguide material having a higher refractive index than the cladding material onto the cladding material and into the waveguide trench pattern, (g) planarizing the waveguide material substantially to the plane of a topmost surface of the cladding material in order to reduce the thickness of the thick coat layer, and (h) forming a layer of additional cladding material to encapsulate the waveguide material in the waveguide trench pattern. An out-of-plane mirror can be used to couple two different layers together optically. A lens element can be used for collimating light reflected by the out-of-plane mirror.