Passively Q-switched diode-pumped Yb:YAG laser using Cr4+-doped garnets

We investigate the repetitive modulation in the kHz frequency domain of a passively Q-switched, diode-pumped Yb:YAG laser, by Cr4+ :YAG, Cr4+ LuAG, and Cr4+:GSGG saturable absorbers. The results presented here are focused towards the design of a passively Q-switched Yb:YAG microlaser. The free-running performance of both rod and a disk Yb:YAG is characterized and experimental parameters such as gain and loss are evaluated. These values, together with the value of the stimulated emission cross-section, e.g. sigma(cm) = 3.3 x 10(-20) cm(2) were found to fit between our experimental results and an existing numerical model which relates the experimental and physical parameters to the minimal threshold pumping power. Q-switched pulses with maximum peak power of approximate to10.4 kW, with energy of approximate to0.5 mJ/pulse, were extracted with 30% extraction efficiency. (C) 2002 Elsevier Science B.V. All rights reserved.