1 Key Laboratory of Infrared Imaging Materials and Detectors, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
Fig. 2. Verification of finite element ray tracing method. (a) Comparison of RMS radii obtained by linear, quadratic and cubic finite element ray tracing with theoretical ones; (b) comparison of RMS radii obtained by cubic finite element ray tracing and theoretical ones at different focal depths behind lens