FUSED-SILICA MASKS FOR PRINTING UNIFORM AND PHASE ADJUSTED GRATINGS FOR DISTRIBUTED FEEDBACK LASERS

A method for producing durable fused silica self-interference grating photomasks is described. These masks allow repeated printing of both uniform and phase adjusted gratings. Periods as fine as 200 nm have been demonstrated. The fabrication of these masks via holographic and focused ion beam lithography and their use as a lithography tool are explained. Distributed feedback lasers, with gratings made by this technique, were produced. These lasers operated in a single longitudinal mode at a wavelength of either 1.55 or 1.3 mum.