讨论了二维光栅光调制器阵列的表面弯曲度对衍射光学特性的影响。利用实测的表面结构数据建立了阵列模型, 利用Matlab软件计算了不同弯曲度对频谱面上衍射光强的分布影响, 得到了弯曲度与对比度之间的关系。结果表明暗态时光栅面的弯曲度对成像对比度的影响很大, 如果将光栅面的中心弯曲度控制在0.1λ以内, 在像面上将获得1000以上的对比度。并通过实验动态显示器件的明暗态调制, 得出减少光栅面弯曲度的优化方案。

The effect the diffractive optical characteristic by the surface bending of two-dimensional grating light modulator (GLM) is disaused. Based on the measured surface structure data, an array model was built, and the effect on diffractive light distribution in spectrum plane with different bendings was calculated by Matlab software. The relation between bending and contrast was deduced. The result indicates that the surface bending can affect the image contrast greatly in condition of darkness. If the bending in center is reduced less than 0.1λ, the contrast will be larger than 1000. An optimized scheme is proposed for reducing the bending of the grating. Through a dynamical experiment which shows the modulation effect of brightness and darkness.