计算全息补偿法制作全息凹面光栅的改进

鉴于计算全息图可以产生一个任意形状的波面,用它作为位相补偿板来制作全息凹面光栅以适应消象差的要求比普通光学全息法更具灵活性,而且消象差波长的选择也不受制作时所用的光源光波波长所限制。本文中采用了离轴滤波及改变参考波面特性等措施,大大提高了计算全息图的空间带宽积,扩大了这一方法的使用范围。对1200l/mm的Ⅲ型及Ⅳ型凹面全息光栅进行了设计,制作及实验验证。

A modified method of using computer-generated hologram In fabricating concave holographic gratings

Using a computer-generated hologram as a compensator to fabricate concave holographic gratings is more flexible in both aberration correction and wavelength selection in comparison with traditional method. In this paper a method of defocusing filtering with a cylindrical wave front used as a reference beam is discussed. With this method, the space-bandwidth product of GGH is obviously increased, thus greatly increasing the range of usage. Using such CGH compensators, 12001/mm concave holographic gratings, both type III and IV, have been fabricated. Experiment results are presented.