摘要：
According to the equivalent circuit model of an optical addressed spatial modulator whose main structure is a-Si;H/Al/FLC, the resolution, response velocity, contrast ratio and gray scale response characteristics were analyzed by Pspice and Matlab. The results indicate that in the condition of certain FLC cell thickness, the resolution of FLC-OASLM can be increased by decreasing the thickness of a-Si: H, but it makes the dynamic range decrease and manufacture more difficult at the same time; the max MTF value is 1 only when the spatial frequency is 0. The output light is very weak when no write light; when write light intensity is from 0. 08 mW/cm2 to 10 mW/cm2, the delay time decreases 110 μs and the rise time decreases 154 μs; when write light intensity is 1 mW/cm2 and erase light intensity is from 0 to 1 mW/ cm2, the delay time increases 41 μs and rise time only increases 3 μs; so the response velocity of FLC-OASLM can be increased by increasing the intensity of write light or decreasing the intensity of erase light in the conditions of certain other parameters. The contrast ratio of FLC-OASLM increases slowly at a low control light intensity, but it increases quickly with the further increasing control light intensity, and finally it is close to a steady value which is 21 :1 in this paper. In the conditions of certain other parameters) the response of output light falls step by step with the increasing intensity of erase light; and after erase light intensity arrives at 3 mW/cm2, the changes of erase light intensity have nearly no effects on the rise time; while the fall time keeps on decreasing with the increasing erase light intensity; more than ten gray scales can be obtained by designing the drive source signal reasonably; so these indicate erase light can realize gray scale function of FLC-OASLM. Simulation results agree with the tested results from others' essays well. The excellent performances make FLC-OASLM have a wide application in the fields of optical information processing and optical imaging.%针对氢化非晶硅/铝/铁电液晶结构的光寻址空间光调制器(OASLM),依据其等效电路模型,利用Pspice和Matlab软件对其分辨率、响应速度、对比度及灰度响应等性能进行了分析.结果表明:在铁电液晶(FLC)层厚度一定的情况下,减小光敏感层(a-Si:H层)的厚度可以提高FLC-OASLM的调制传递函数,从而提高分辨率；在其他参量一定的情况下,FLC-OASLM的响应速度随写入光光强增大而增大(写入光从0.08 mW/cm2增大到10 mW/cm2,延迟时间减小110 μs,上升时间减小154μs),随擦除光光强增大而减小(擦除光从0增大到1 mW/cm2,延迟时间增大41 μs,上升时间仅增加3 μs)；FLC-OASLM的对比度随控制光光强增大而增大,最终趋于一个稳定值21:1；在其他参量不变时,随着擦除光光强的增大,输出光响应呈现“等级”下降,且发现当擦除光光强达到一定值(3 mW/cm2)后,擦除光的改变主要影响下降时间而对上升时间几乎无影响；合理设计激励源信号波形,可以得到超过十级灰度输出,表明擦除光具有实现FLC-OASLM的灰度响应的功能.
