All-solid-state diode and end-pumped Nd:YAG laser passively Q-switched by Cr4+:YAG saturable absorber

A diode end-pumped Nd:YAG laser passively Q-switched by Cr 4+ :YAG saturable absorber and intracavity frequency-doubled by a LBO nonlinear crystal is described. Using a linear cavity the maximum average power at 1.06-μm fundamental wavelength was 3.3 W, 22.5 kHz repetition rate and 25.2-ns pulses duration. The maximum peak power was 12 kW for an average power of 1.8 W, laser pulses of 17.5-ns duration and 209.3-μJ energy. Intracavity frequency-doubling employing a V-type laser resonator yielded 532-nm green pulses of 226-μJ energy and 86-ns width at 4.2-kHz rate of repetition. The theoretical calculations based on a model of rate of equations show good agreement with the experiments at both fundamental and second-harmonic wavelengths.