【摘要】 从实验上研究了不同外加直流电场作用下固液同成分的SBN∶Cr和SBN∶Rh晶体的光致折射率变化规律 测量结果表明 :无外加电场作用时 ,晶体中的光致折射率变化不明显 ;若在光辐照晶体的同时 ,沿晶体c轴方向施加一定方向的外电场 ,则晶体中即刻出现显著的光致折射率变化 这种折射率变化随外加电场的增大而增大 ,并且电场方向不同 ,折射率变化的正负也不同 因而可以通过改变外加电场的极性和幅度控制SBN∶Cr和SBN∶Rh晶体中光致折射率的变化特性 ,这对于在该类晶体中制作动态光波导具有重要意义更多还原

【Abstract】 The light-induced refractive index changes in congruent SBN∶Cr and SBN∶Rh crystals are experimentally investigated.A thin sheet beam from a He-Ne laser is used to irradiate the crystal sample, and simultaneously, an external direct electric field is applied along the crystal c-axis with different polarity and amplitude. The experimental results indicate that there are almost no index changes to be observed in the irradiated zone of both crystal samples SBN∶Cr and SBN∶Rh without the presence of external field. When irradiating the crystal by laser beam on the condition of applying an electric field along the c-axis, the index in the irradiated zone of the both crystals is quickly and obviously changed. The change values increase with the increasing of external field and their signs can be controlled by the orientation of external field. Therefore these properties may be employed to fabricate dynamic waveguide and optical switch in SBN∶Cr and SBN∶Rh crystals by light-irradiation in the presence of external field.更多还原