The basic structure and the fundamental principle of semiconductor saturable absorption mirrors(SESAM) that are used for passive mode-locking solid-state lasers are introduced.By using these mode-locking devices on novel thin-disk solid state lasers and optically pumped vertical-external-cavity surface-emitting semiconductor lasers(OPS-VECSEL) to obtain high average output power ultrashort pulses are stated,and it is emphasized that the study of high average output power ultrashort pulses laser can be accel...