Two-color photorefractive holography in Mn-doped near-stoichiometric lithium niobate crystals

Holograms are recorded in near-stoichiometric LiNbO 3 doped with 8 ppm of Mn by use of two-color holographic recording method, where an IR laser of 778 nm is used for writing and an UV laser of 350 nm is used for gating. Dependences of two-color sensitivity and M/# on gating and writing intensities are presented. Significant improvements of sensitivity, M/# and dark decay are obtained compared with reduced near-stoichiometric LiNbO 3 . To our knowledge, the measured two-color sensitivity of 0.21 cm/J with a gating intensity of 1.5 W/cm 2 is the highest among the values reported so far, which is attributed to large light-induced absorption of small polarons. 50 plane-wave holograms are recorded by the conventional angle-multiplexing method.