Yb:YAG enhanced Cr,Yb:YAG self-Q-switched microchip laser under QCW laser-diode pumping

• Efficient Yb:YAG/Cr,Yb:YAG microchip laser has been demonstrated under QCW laser-diode pumping.
• Effects of pump pulse duration and pump power on Yb:YAG/Cr,Yb:YAG microchip lasers have been studied.
• Efficiency of 24.3% was achieved in QCW laser-diode pumped Yb:YAG/Cr,Yb:YAG microchip laser.
• The Q-switched laser pulses with pulse energy of 31 μJ and peak power of 13.3 kW were obtained.
• New technology for developing efficient high peak power passively Q-switched microchip lasers.

Enhanced Cr,Yb:YAG self-Q-switched microchip lasers by bonding Yb:YAG crystal have been studied under quasi-continuous-wave (QCW) laser-diode pumping for the first time to our best knowledge. The effects of the pump pulse duration and pump power of the QCW laser-diode on the performance of Yb:YAG/Cr,Yb:YAG microchip lasers have been investigated. The optical efficiency, pulse energy and peak power of the Yb:YAG/Cr,Yb:YAG self-Q-switched laser increase with the pump pulse duration and pump power, and tend to be constant when the pump pulse duration is longer than 1 ms, which is comparable to the fluorescence lifetime of Yb:YAG crystal. Output energy of over 11.7 mJ was obtained at input pump energy of 48.2 mJ; corresponding optical-to-optical efficiency of 24.3% was obtained. Laser pulses with pulse energy of 31 μJ and peak power of 13.3 kW were obtained. The multi-longitudinal modes oscillation around 1030 nm was dominant within the available input pump energy.