Abstract
Based on the quasi-three-level system, a theoretical model of diode-laser end-pumped fundamental continuous-wave (CW) Yb3+:YAG microchip lasers is proposed. The fluorescence concentration quenching effect, the temperature dependent mechanical and optical properties and the absorption efficiency of the host have been taken into account in the model. The theoretical results of the numerical calculations are in good agreement with those of experiments. The effects of the concentration of the Yb3+:YAG crystal, the thickness of the Yb3+:YAG crystal, the temperature and the transmission of the output coupler on the laser performance (threshold and output power) are addressed. The optimization of the concentration and the thickness for the Yb3+:YAG crystal microchip laser is presented. The effects of the temperature and the pump power intensity on the optical-to-optical efficiency are discussed. The output power can be scaled by increase the working area of the laser gain medium. This modeling is not only applicable to Yb3+:YAG crystal microchip laser but also to other quasi-three-level microchip lasers.