Passively Q-switched Cr:LiCAF laser with a saturable Bragg reflector

We present a low-cost multimode diode pumped passively Q-switched Cr:LiCAF laser operating near 800 nm. AlGaAs-based saturable Bragg reflectors (SBRs) were used for passive Q-switching. The system is experimentally characterized in detail using four different output couplers and two SBRs with different modulation depths. Pulse widths in the 1.5-4 mu s range at repetition rates between 18 and 40 kHz were achieved with average powers up to 125 mW. The experimentally obtained results are compared with basic Q-switching theory and further performance improvement in terms of pulse length shortening and peak power scaling is elaborated.