Control the Output Characteristic of Dy2+:CaF2 Passively Q-Switching Ruby Laser

The passive Q-switched performance of the ruby laser with slow-relaxing solid-state saturable absorber calcium fluoride crystals doped with divalent dysprosium Dy²⁺:CaF₂ is numerically investigated by solving the coupled rate equations with the Runge-Kutta-Fehlberg method. In the mean time, important factors such as the laser population inversion at various stages, the peak photon number inside the laser resonator, the output energy and the pulse width of the Q-switched laser output are computed. For typical configuration, a Q-switched laser pulse of 150 ns in duration and 3 mJ in energy is obtained. Also the effects of the pumping rate, reflectivity of output coupler, and saturable absorber doping concentration on output laser characteristics are studied. The simulated results show reasonable agreement with those obtained experimentally by other research groups.