Ultraviolet laser pulses (λ = 355 nm) sensitize photorefractive iron-doped lithium tantalate crystals (LiTaO3:Fe) for subsequent infrared (λ= 1064 nm) holographic recording. Non-destructive readout with infrared light is possible and the holograms remain erasable for ultraviolet light. Refractive-index changes up to 1.6×10−4 are achieved for intensities of the infrared light of 1011 W/m2, The saturation values are proportional to the concentration of Fe3+ ions. Typical time constants of recording and erasure are 0.5 μs for intensities of the ultraviolet light of 1011 W/m2. The results can be explained by a two-center charge-transport model.
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