Growth and photorefractive properties of In:Fe:LiNbO_3 crystals with various [Li]/[Nb] ratios

摘要

In:Fe:LiNbO_3 crystals with various [Li]/[Nb] ratios were grown by the Czochralski method from melts having compositions varying between 48.6 and 58mol% Li_2O. The crystal composition and defect structure were analyzed by the UV-Vis and IR spectroscopy. The photorefractive properties of the In:Fe:LiNbO_3 crystals were experimentally studied by using the two-wave coupling method. The results of the two-wave coupling experiments showed that as the [Li]/[Nb] ratio increased, the diffraction efficiency decreased, but the holographic response time and photorefractive sensitivity increased. Among all samples, the dynamic range of the In:Fe:LiNbO_3 crystal with [Li]/[Nb] ratio of 1.2 was the largest (up to 10.22).