The instantaneous pulse evolution in active mode-locked laser

By setting up a suitable active mode-locked mode,the evolution process of a instantaneous pulse is simulated with a numerical calculation method.The simula-tion results show that the primary radiation come to a stable mode-lock state only after 1～1.5ms reflections(about 1 ms).With a simple method,the evolution time of a mode-locked pulse measured experimentally.This experimental result is consistent with theory calculation basically.