不同记录光强下辅助紫光对菌紫质薄膜全息衍射效率的影响

具有光致变色效应的菌紫质薄膜可用作可擦重写型全息记录介质. 在全息记录过程中，由于菌紫质薄膜对记录光的散射和反射引起记录光栅对比度下降，当记录光较弱时，这种影响较小，可以忽略；但当记录光较强时，散射和反射光对记录光栅的影响很大，必须考虑它们对光栅对比度的影响才能对实验结果进行合理的解释. 实验发现在不同的记录光强下辅助紫光对衍射效率动力学曲线的影响不同，当记录光强较弱时，加入辅助紫光可以提高衍射效率的稳定值、抑制峰值；而当记录光强较强时，加入辅助紫光除了提高衍射效率的稳定值外，还可以提高衍射效率的峰值. 关键词：菌紫质衍射效率干涉条纹对比度

Influence of auxiliary violet light on holographic diffraction efficiency under different recording intensities in bacteriorhodopsin film

The photochromic bacteriorhodopsin (BR) film can be used as a rewritable holographic recording medium. Due to the scattering and the reflecting of light from the BR film, the grating contrast of the hologram is diminished during the hologram recording. When the intensity of the recording light is weak, the influence of the scattering and reflection on the grating contrast is low enough to be neglected. But in the case of intense recording light, this influence should not be overlooked. It is found that the influence of the auxiliary violet light on the holographic diffraction efficiency kinetics is distinct under different recording intensities. At weak recording light intensities, the steady diffraction efficiency are increased and the peak diffraction efficiency is suppressed by the auxiliary violet light. But for intense recording light, the steady diffraction efficiency as well as the peak diffraction efficiency are both increased by the auxiliary violet light. Based on the two-level model of BR photochromism, we give a good theoretical explanation to the above phenomena.