光折变晶体中全息图的热固定过程研究

报道了Fe∶LiNbO3和Ce∶Fe∶LiNbO3晶体中红光波段记录的光栅的热固定实验 ,详细描述了光折变晶体中全息图热固定的定影和显影工艺。在定影过程中测量了光栅峰值衍射效率随温度的变化。显影实验表明用原参考光显影会引起光栅的自增强衍射、布拉格角偏移、选择角增宽和背景噪声增加 ,采用非相干光显影可避免这些缺点。提出了一种降低光相干性的方法 ,从而可以采用原记录光路进行显影。

Study on Thermal Fixing Process of Holograms in Photorefractive Crystals

In this paper, the technology of fixing and developing of thermal fixing of holograms in photorefractive LiNbO 3 crystals is described in detail. The dependence of the peak diffraction efficiency of grating on the temperature was measured at fixing stage. The experimental results of developing show that developing by reference beam usually suffer from self enhancement, Bragg angle shift, selective angel broadening and scattering noise increasing. Developing by incoherent light can avoid these disadvantages. In this paper, a method of decreasing coherent degree of light is proposed for developing by original recording optical set up.