Diode-pumped doubly passively Q-switched Cr,Nd:YAG/KTP green laser with GaAs saturable absorber

A diode-pumped doubly passively Q-switched Cr,Nd:YAG/KTP green laser with GaAs saturable absorber is realized for the first time to our knowledge. This laser can generate a more symmetric and shorter pulse when compared with the self-Q-switched Cr,Nd:YAG/KTP green laser. A symmetry factor is defined to describe the temporal symmetry of the pulses. At an incident pump power of 4.1W, a pulse symmetry factor as high as 0.995 is obtained. A rate equation model is introduced to theoretically analyze the results obtained in the experiment, in which the spatial distributions of the intracavity photon density, the pump beam and the population-inversion density are taken into account. The numerical solutions of the rate equations are in good agreement with the experimental results.