Photorefractive effect of Fe:KLN crystal

We have grown KLN and Fe:KLN crystals using the TSSG method. The crystal lattice constants are measured by the X-ray diffraction technique and the crystal optical absorption edges are characterized by an ultraviolet-visible absorption spectrum measurement. The results show that the absorption edge of the Fe:KLN crystal shifts to the longer wavelengths compared with that of the KLN crystal. The exponential gain coefficient and erasure time are examined by two-beam coupling experiment. The results indicate that the exponential gain coefficient of Fe:KLN crystal is twice as large as that of the KLN crystal, and the photoconductivity of the Fe:KLN is three orders of magnitude higher than that of KLN. The enhancement of photorefractive properties of Fe:KLN crystal is also discussed.