随着现代光学测试技术的不断发展，对图像处理技术的要求越来越高。灰度级层次蕴含了图像细节的重要信息，因此改变图像灰度级可以使图像的细节更清晰。通过滤光技术可以形成不同的灰度级。依据光学薄膜理论，并结合膜系设计软件，通过建立膜系优化评价函数，实现了0°~60°入射3~5 μm滤光膜的设计，并采用真空沉积技术研制了灰度调节膜。通过在钼舟上方放置铜网，解决了由于SiO沉积速率不稳定产生的膜层表面缺陷的问题；采用逆向分析法对实验测试结果进行模拟，通过调整膜层监控方式，使膜系的敏感层厚度得以精准控制，降低了膜厚控制误差，从而平滑了光谱曲线。经过测试，制备的灰度调节膜满足红外成像系统灰度级调节的要求，并通过了相关环境测试。

With the continuous development of modern optical testing technology, the requirement of image process technology is increasing. As the gray-scale level contains important information of image, changing gray levels of the image can make the image detail more clear. Using filter technology can form different gray levels. Based on the optical thin film theory and combined with thin film design software, the design of a 3~5 μm thick filter film with incident angle of 0°~60° is achieved by establishing film optimization evaluation function. And using vacuum deposition technology, the gray adjustment film is fabricated. Adding copper mesh over the molybdenum boat can solve the problem of surface defects caused by the unstable deposition rate of SiO. The experimental results are simulated using reverse analysis method. The sensitive layer thickness of film system can be controlled by adjusting the film monitoring method. The controlled deviation of film thickness is reduced. So that the spectral curve is smoothed. After tests, the prepared film meets the requirement of gray adjustment in the infrared image system, and passes the relevant environmental tests.