The Investigation Of The Photorefractive Effect In LiNbO₃ Doping With Vanadium

Because of its good electro-optic property, Lithium niobate crystal plays a key role in photorefractive research and applications. As an important kind of synthetic crystal, We can use different dopants to depress or enhance photorefraction effect in LN for different applications。Mg2+, Zn2+, In3+,Hf4+, Zr4+ and Sn4+ are conventional damage-resistant irons, especially LN:Zr are attracting more and more researchers for its excellent photo-damage resistance ability in ultraviolet-visible wavelength range。some transition-metal irons, such as Cr, Cu, Fe, Ce, Mn, are usually used to enhance the photorefractive effect, and LiNbO3:Fe has better properties of high diffraction efficiency and sensitivity, however, there exists some intrinsic shortcoings, such as serious light-induced scattering and low response, and in spite of many improvement, its properties can not well satisfy our applications, we need new photorefractive materials.We grew a series of LiNbO3 doped with Vanadium by the Czochralski method as follows:[1]:LiNbO3:V. The congruent composition was selected as [Li]/[Nb]=48.38/51.62. Their Vanadium concentrations are 0.1,0.2,0.3,0.4, 0.5,0.7,1.0 and 2mol%, respectively. [2]:LiNbO3:Zr:V. the Vanadium concentration is 0.1 mol% and ZrO2 are 1,2, and 3 mol % respectively. With the help of XPS and EPR, we measured Vanadium valence states:+3,+4,+5. and V3+ and V4+ ions are corresponding to the 420 nm and 475 nm absorption peaks respectively. The fast photorefractive response (0.167s), moderate diffraction efficiency, high sensitivity indicate that LN:V is a suitable candidate for ultraviolet photorefractive applications. At the same time, the holographic properties of LN:V and LN:Zr:V are given at 532 nm.