Ultrashort-pulse generation using VECSELs and MIXSELs

Optically pumped SESAM modelocked semiconductor disk lasers (SDLs) or vertical-external-cavity surface-emitting lasers (VECSELs [1]) (Fig. 1a) are of great interest for applications that require compact and high-power sources with ultrashort pulses and excellent beam quality. The modelocked integrated external-cavity surface emitting laser (MIXSEL [2]) (Fig. 1b) combines the gain of VECSELs with the saturable absorber of a semiconductor saturable absorber mirror (SESAM) in a single semiconductor device. Hence, self-starting and stable passive modelocking is obtained in a simple straight cavity formed by the semiconductor chip and a curved output coupler (Fig. 2a). Record high average output power of 6.4 W from a picosecond MIXSEL confirmed the high potential of this technology.