GaSb-based VECSEL for high-power applications and Ho-pumping

The (AlGaIn)(AsSb) material system has been shown to be ideally suited to realize VECSELs for the 2-3 mm wavelength range. In this report we will present results on increasing the output power of the SDL chips with special emphasis on the 2.8 mm emission wavelength by means of low quantum defect pumping. Further on we have investigated concepts for a VECSEL-pumped Q-switched Ho:YAG laser in order to convert the high cw-power of the VECSEL into pulses with a high peak power. Up to 3.3 mJ of pulse energy were achieved with a compact setup (corresponding to a peak power of 30 kW at 110 ns pulse length) combined with stable pulsing behavior.