Study on Holographic properties of Mg:Ce:Fe:LiNbO_3 crystal

摘要

Congruent Ce(0.1mol%):Fe(0.03wt%):LiNbO_3 crystals doped with different concentrations of 2.0mol%, 4.0mol% and 6.0mol% MgO were grown by the Czochralski method. The effects of Mg-doping on UV absorption edge and OH~- absorption peak were investigated by absorption spectra and infrared spectra. The mechanism of the absorption edge shifting and OH~- absorption peak shifting was investigated. Using He-Ne laser as light source, the photorefractive properties such as the writing time, erasure time, diffraction efficiency, dynamic range and sensitivity of the samples were experimentally studied by two-beam coupling. It is found that the holographic properties of the Mg:Ce:Fe:LiNbO_3 crystals are improved when compared with Ce:Fe:LiNbO_3 crystal's. The doping mechanism is discussed using the Li-vacancy model.