SIMULTANEOUS FABRICATION OF OPTICAL CHANNEL WAVE-GUIDES AND OUT-OF-PLANE BRANCHING MIRRORS FROM A POLYMERIC SLAB STRUCTURE

Recently, polymeric multimode optical waveguides have been widely stud ied for low-cost interconnection use. We describe fabrication processe s for a low-loss poly(methyl methacrylate) (less than 0.1 dB/cm at 675 nm) waveguide based on the reactive-ion-etching technique and for a s lope (45 degrees mirror face) formed on the waveguide. To obtain a rid ge core with a crack-free and extremely smooth surface, we applied a h eating process at a temperature greater than the glass transition poin t and a smoothening process by solvent. Furthermore, to fabricate simu ltaneously both vertical and sloped sidewalls, we applied a unique phe nomenon in the process that decreases the etching rate directly under a narrow opening of etching mask. By using the above fabrication techn iques, we demonstrated an out-of-plane branching mirror. (C) 1997 Opti cal Society of America.