2-COLOR HOLOGRAPHY IN REDUCED NEAR-STOICHIOMETRIC LITHIUM-NIOBATE

We explored a number of factors affecting the properties relevant to h olographic optical data storage by using a two-color recording scheme in reduced, near-stoichiometric Lithium niobate. Two-color, or photon- gated, recording is achieved by use of 852-nm information-carrying bea ms and 488-nm gating light. Readout at 852 nm is nondestructive, with a gating ratio of similar to 10(4). Recording sensitivity, gating rati o, dynamic range, and dark decay were measured for crystals of differi ng stoichiometry, degree of reduction, wavelength of the gating light, temperature, and optical power density. The two-color sensitivity per incident photon is still somewhat less than that of the one-color pro cess at 488 nm for similar to 1 W/cm(2) of gating light but is essenti ally the same in terms of absorbed photons. Two-color recording is an attractive way of achieving nondestructive readout in a read-write mat erial, and it allows selective optical erasure. (C) 1998 Optical Socie ty of America.