紫外像增强器分辨力和视场质量测试技术研究

Resolution and FOV quality of UV image intensifier

为了对紫外像增强器的光学成像特性和视场质量进行分析,提出一种紫外像增强器分辨力和视场质量的测试方法。该方法是在具有典型波长254nm的紫外光辐射光阴极的条件下,给像增强器施加工作电压,将测试分划靶聚焦在同轴反射式光学系统的焦面上,图像被缩小3倍并成于像增强器荧光屏上,通过调节物镜和目镜将图像调节清晰可见,借助放大30倍的视频显微镜观察图像能分辨的最低线对就是分辨力;用数码相机对荧光屏所成像进行拍照,经图像处理软件对所成像进行疵点大小和分区划分,给出视场质量测试结果。通过建立该测试装置,进行试验和结果分析,测量精度约5%。

To analyze the optic imaging characteristics and the FOV quality of ultraviolet （UV） image intensifier, a method for testing the resolution and FOV quality of UV image intensifier was put forward. Under the condition of the photocathode irradiated by the typiCal 254nm UV light, we applied working voltage on the image intensifier, focused the testing targets on the focus plane of the coaxial reflect optic system, and the image was trebly reduced on the screen of image intensifier. The imaging could be seen distinctly by adjusting the objective and ocular, and the lowest line pair observed by 30× video microscope was the resolution. We used digital camera to take photo of the image on the screen, and the spots were measured through image processing software. The testing results of the field showed that the measurement precision was about 5 %,which validated the feasibility of the testing method.