Light-induced absorption changes in in-doped congruent LiNbO3

We investigate visible and near-infrared light-induced absorption changes caused by intrinsic defect centers in congruently melting and reduced LiNbO3:In with a single-shot picosecond pulse at 532 nm. It is found that the dark decay dynamics of optically induced shallow centers strongly depend on In concentrations. Two types of optically induced shallow centers having dark decay time constants on the orders of milliseconds and tens of microseconds are observed in LiNbO3 doped with In below the damage-resistant threshold concentrations. Only one of the two types is observed in LiNbO3 doped with In above it. The origin of these shallow centers is also discussed. (C) 2002 American Institute of Physics.