Fabrication of photonic waveguides in sulfide chalcogenide glasses by selective wet-etching

A selective wet-etching method for micro-fabricating As₂S₃ glass ridge waveguides, using CS₂ solution with iodine as an oxidising reactant, has been developed. The proposed method is based on photo-induced changes in chalcogenide glasses, and therefore can be free of photomasks and photoresists. The optical properties of such etched ridge waveguides have been tested and they exhibit a more than 2 dB/cm loss reduction compared to laser direct-written channel waveguides.