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Volume gratings for holographic storage applications written in high-quality germanosilicate glass.

Volume holographic gratings are written with ultraviolet light in high-optical-quality, commercially available Ge-doped silica films and in Ge-doped optical-fiber preform sections loaded with molecular hydrogen. In the film samples, peak refractive-index changes exceeding 10(-2) and a sensitivity (index change/absorbed energy density) of 0.4 × 10(-7) cm(3)/J are measured. Angular multiplexing of up to 51 gratings is demonstrated in the preform samples.