Simulation of the influence of gain and SESAM on characteristics of mode-locked VECSELs

Vertical external cavity surface-emitting lasers (VECSELs) have unique properties such as excellent beam quality, high average output power, and high repetition rate. Short pulses from VECSELs, especially picosecond and femtosecond, can be achieved by a passive mode-locking mechanism with a semiconductor saturable absorber mirror (SESAM). We theoretically simulate the pulse evolution dynamics in VECSELs and investigate the influences of different parameters of gain and SESAM on pulse characteristics. To the best of our knowledge, this is the first time that the influences of fast recovery time and two-photon absorption coefficient on pulse characteristics have been studied.