Efficient, nanosecond self-Q-switched Cr,Yb:YAG lasers by bonding Yb:YAG crystal

Efficient laser-diode pumped self-Q-switched Cr,Yb:YAG lasers by bonding Yb:YAG crystal to increase pump power absorption efficiency have been demonstrated for the first time to our best knowledge. The effect of transmission of output coupler (TOC) on the laser performance has been investigated and found that the best laser performance was achieved with TOC = 50%. Average output power of 1 W was obtained with TOC = 50% at absorbed pump power of 5.4 W; corresponding optical-to-optical efficiency of 18.5% was obtained with respect to the absorbed pump power. Slope efficiency of 25% was measured with TOC = 50%. Laser pulses with pulse width of 26 ns, pulse energy of 37 μJ, and corresponding peak power of 1.4 kW with TOC = 50% were obtained. The lasers oscillate in multi-longitudinal-mode; number of the modes increases from two to five with pump power, owing to the mode selection by Cr,Yb:YAG thin plate acting as an intracavity etalon