SILICA GERMANIA GLASS COMPOSITIONS

摘要

It has been demonstrated that silica/germania glasses in reduced form are more sensitive to radiation in the band 225-275 nm and, therefore, reduced silica/germania glasses are particularly adapted to receive refractive index modulation, e.g. to make reflection gratings. The reduced compositions of silica/germania are identified by an absorption of more than 200 dB/cm/wt% of Ge. The reduced compositions are conveniently obtained by subjecting the glass to a non-oxydising atmosphere, e.g. helium preferably while it is in a porous state or in the form of a thin film.