Abstract: A technique combined domain decomposition and staged ray splitting is presented to decrease computational complexity by reducing surfaces and rays for intersections solution.Domain decomposition is based on relation between sub-zone and number of surfaces.Splitting ratio is determined with propagation information of stray light.A suppression structure and a multi-sensor system are analyzed.It shows that the technique can improve computational efficiency while maintaining acceptable accuracy.

Key words: stray light, Monte Carlo method, domain decomposition, staged ray splitting