Photorefractive properties for holographic application of Ce:Fe:LiNbO3 crystals with various [Li]/[Nb] ratios

Ce:Fe:LiNbO3 crystals with various [Li]/[Nb] ratios were grown by the Czochralski method from melts having compositions varying between 48.6 and 58 mol% Li2O. The Ce, Li and Nb concentrations in the grown Ce:Fe:LiNbO3 crystals were analyzed by the inductively coupled plasma atomic emission spectrometer (ICP-AES). It was found that as the [Li]/[Nb] ratio increases in the melt, the [Li]/[Nb] ratio in the crystal and the distribution coefficients of Ce ions increase also. The photorefractive properties of the Ce:Fe:LiNbO3 crystals were experimentally studied by the two-wave coupling method. The results show that as the [Li]/[Nb] ratio increases, the dynamic range decreases, but the photorefractive sensitivity and the signal-to-noise ratio improve. In a coherent volume 0.192 cm3 of a Ce:Fe:LiNbO3 crystal with [Li]/[Nb] ratio of 1.2, 3800 holograms with 800×600 pixels have been successfully multiplexed in a compact volume holographic data storage system.

► Ce:Fe:LiNbO3 crystals with various [Li]/[Nb] ratios as holographic storage materials. ► The Li and Nb concentrations in the samples were analyzed. ► The effective distribution coefficients of Ce in the samples were calculated. ► As the [Li]/[Nb] ratio increases, the photorefractive properties are improved. ► High-density holographic data storage (9.5 Gbits/cm3) has been achieved.