基于斯特林制冷式4×288元光伏型碲镉汞二维探测器, 根据红外扫描成像系统原理, 设计了一个扫描型长波红外连续变焦光学系统。根据系统指标要求对光学指标进行分解计算及光学优化设计得到系统的光学参数和外形结构图, 并对扫描光学系统的冷反射进行分析优化。该光学系统采用三次成像的结构, 由变焦望远镜组、扫描摆镜、中继镜组、成像镜组4部分组成, 包含9片透镜和2片反射镜。为了降低校正色差成本, 系统使用了硫系玻璃镜片。光学仿真结果表明:系统在耐奎斯特频率处的全视场光学传递函数大于0.35, 全视场畸变小于2%。最后, 对系统进行了成像实验验证, 结果表明:该系统可以实现30.8~154 mm范围内连续变焦, 变焦过程中目标景物清晰, 细节分辨率高, 无冷反射现象出现, 该系统具有分辨率高、热灵敏度高、像质清晰等特点。
Using infrared scanning system principle, a novel long-wavelength continuous zoom scanning optical system is presented based on 4×288 infrared MCT detector dewar cooled assembly. Related optical index parameters are resolved and calculated according to requirements of system, and the optical design parameters and outside view are obtained by the optical design software. The narcissus effect of the scanning optical system are analyzed and optimized. The optical system is composed of zoom telescope, scanning mirror, relay lens, imaging lens and a tertiary imaging system including nine lenses and two reflectors. In order to reduce cost and optical color aberrations, chalcogenide glass lens is used. The optical index is simulated, and the MTF in whole field at Nyquist frequency is over 0.35 and distortion is below 2%.Finally the system imaging experimental verification is conducted. The results indicate that 30.8~154 mm continuous zoom and 100% cold shield efficiency are achieved. High resolution, thermal sensibility, excellent images are validated.