Two-photon apodization in lithium niobate.

We demonstrate a novel apodization technique for holographic data storage using two-photon recording in stoichiometric lithium niobate. The gating light-intensity profile is used to achieve grating apodization inside the bulk of the crystal during recording in the transmission geometry. Experimental Bragg-selectivity curves and theoretical fits indicate a >20-dB drop in multiplexing cross talk.