Comparative performance of passively Q-switched diode-pumped Yb3+-doped tungstate and garnet lasers using Cr4+:YAG saturable absorber

We investigated the continuous wave (CW) free-running and repetitive modulation in the kilohertz frequency domain of a passively Q-switched diode-pumped Yb:YAG, Yb:GGG, and Yb:KYW lasers by using Cr4+ NAG as a saturable absorber. The results presented in this paper are focused on the design of a passively Q-switched Yb-doped garnets or Yb-doped tungstates microlasers. The free-running performance of Yb:YAG, Yb:GGG, Yb:KGW, and Yb:KYW were characterized, and experimental parameters such as gain and loss were evaluated. We carried out a fit between our experimental results and an existing numerical model, which relates the experimental and the physical parameters of the ytterbium diode-pumped system to the minimal threshold pumping power. The best performance among the laser crystals was obtained for Yb:YAG laser. A maximum peak power of approximate to 4.5 kW at an average output power of 1.32 W was extracted with an extraction efficiency of approximate to 25 %.