Dear Zhang Kaiyuan Sir, For the last ten years, the company OPTIS has worked on non imaging system design software. The software is needed to simulate a complete photometric path that could take into account all the major needs of optronic system designers. Different ways of simulation the system photometry will be described, showing the improvement which has come through experience. The analysis and simulation include different parts of an optronic system. The main input data includes: characterization of sources in the near and far fields, thermal emission information, geometrical data, and the surface and volume properties of materials. The emission and propagation of radiation through the system with the material interactions (refraction, reflection and scatter) are simulated for coherent and incoherent light. The simulation uses a Monte Carlo method which has been improved for use in stray light analysis. The main research emphasis has been on developing and testing algorithms to reduce the calculation time without sacrificing precision. 

Awesome,thank you very much.I will study about the software of OPTIS.