LiNbO_3晶体中光折变热固定过程的准实时可视化研究

Quasi-real-time Visualizations of Dynamics of Light-induced Index Changes During Thermal Fixing in LiNbO_3 Crystal

采用数字全息术对LiNbO3∶Fe晶体中高斯光束诱导的折射率变化热固定过程进行了准实时可视化实验研究·实验过程中通过在线加热的方式对光致折射率变化进行固定,采用冷光源提供的非相干白光对热固定的折射率变化进行显影·通过数值再现得到热固定过程中不同阶段的折射率变化分布,根据折射率变化的演化过程确定出了显影的最佳时间·

The dynamics of Gaussian-beam-induced index changes in LiNbO3： Fe crystal during thermal fixing are visualized in quasi-real-time by using digital holography. The on-line method is employed to fix the light-induced index changes, and an incoherent white beam emitted from a cold light source is used to develop the fixed index changes. By numerically reconstructing the recorded digital holograms, the distributions of light-induced index changes corresponding to different stages of thermal fixing can be obtained. The results illustrate that the reversal of the Gaussian-beam-induced index changes during thermal fixing are visualized in quasi-real-time successfully by employing the digital holography, and the optimal developing time can be obtained by monitoring the evolvement of light-induced index changes.