摘要
研究了两种典型的光束几何配置下 ,Li Nb O3:Fe晶体的光感应光散射。实验表明 ,晶体散射图样的几何结构相同 ,强度分布和偏振状态不同。在双光束作用下 ,以双光束为公共母线、以其交点为顶点形成四个散射光锥 ,各向异性散射出现在 c轴方向。入射光束偏振平面平行于光轴时比垂直于光轴时更易产生光感应光散射。讨论了光生伏打电流以及衍射效率与入射光的角度关系对光感应光散射空间分布和时间特性的影响。结果表明 ,光感应光散射不仅与光生伏打电流的方向有关 。
Signal noise ratio(SNR) of recorded hologram is reduced by light induced scattering (LIS) in LiNbO 3:Fe crystals. We carried out experiments to investigate LIS in LiNbO 3:Fe crystal by two beams interference interaction in two typical geometric configurations. We observed the features of LIS and measured the dependence of LIS intensity on time by two beams illuminating in LiNbO 3:Fe crystal. It is shown that two incident beams whose polarized planes are parallel to c axis produce LIS more easily than beams whose polarized planes are orthogonal to c axis. Symmetrical rotation axes of anisotropic and isotropic scattering cones caused by both configurations are in the directions of ± c axis and ⊥ c axis, respectively. In addition, the space distributions and time characteristics of scattered light intensity are interpreted rationally with bulk photovoltaic currents and the dependence of diffraction efficiency on the angle of incident beam. In conclusion, when the geometry between two beams and crystal for holographic storage is properly chosen, SNR of recorded hologram can be improved.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2000年第2期190-193,共4页
Journal of Northwestern Polytechnical University
关键词
光感应光散射
全息写入
晶体
light induced scattering, holographic write in, LiNbO 3:Fe crystal, bulk photovoltaic current
