Film or stripe waveguide structure - with optical grating formed at waveguide edge face

摘要

Prodn. of an optical grating (3) on the small edge face (100) of an optical film or stripe waveguide (1) is carried out using an etch mask (2) which covers the waveguide flat surface (10) and which has an edge (20) defining the edge face contour to be etched along the mask edge (20). The novelty is that the mask edge (20) has comb tooth-like projections (21) defining the grating (3) and that the masked waveguide surface (10) is etched with an etchant which only etches perpendicularly to this surface. Also claimed is a film or stripe waveguide structure in which an optical grating (3) is formed on a small waveguide edge face (100) running along a given line (8), the grating lines being defined by projecting ribs (31) and/or recessed grooves (32) which are vertical to the waveguide surface (10). The novelty is that the ribs (31) and/or grooves (32) have a rectangular profile. USE/ADVANTAGE - The process is useful for prodn. of wavelength multiplexers and demultiplexers. It combines the high resolution of holographic exposure with the alignment precision of mask exposure and employs only low cost technology.