The effect of In3+ doping on optical properties of Fe:LiNBO3 crystals

Fe:LiNbO3 and In:Fe:LiNbO3 crystals were grown by Czochralski method. The absorption spectra were measured to investigate their defect structure. The photo damage resistance and photorefractive properties were measured. The photo damage resistance of the In:Fe:LiNbO3 crystal in which the In concentration is above the threshold value is one order of magnitude higher than that of the Fe:LiNbO3 crystal. The mechanisms of the violet shift of the absorption edge and the enhancement of the photorefractive effect of In:Fe:LiNbO3 crystals were investigated.