VOLUME HOLOGRAPHIC STORAGE IN HYDROGEN TREATED GERMANO-SILICATE GLASS

Strong permanent gratings (index change Delta n similar to 3 X 10(-3)) have been formed in bulk hydrogen treated germane-silicate glass with 242 nm exposure. Diffraction efficiencies of 6% and initial sensitivi ty (Delta n/incident energy density) of 2 X 10(-5) cm(2)/J have been o btained. The observed sensitivity is comparable to the values achieved in other holographic storage materials such as LiNbO3. It is estimate d that by more uniform hydrogen loading of the sample, diffraction eff iciencies of 100% can be obtained in 3 mol % GeO2 samples of only 175 mu m thickness. These materials are potentially useful as fast access time (sub-mu s), high capacity (similar to 0.8 Tbits), robust, inexpen sive write-one-read-many storage media, narrow (subangstrom) linewidth optical filters, and other optical components.