We present a new model for cw, Yb-doped, bulk crystal lasers emitting on a three-level laser transition near 980 nm. This model takes into account the saturation of the absorption and the spatial evolution of the pump and laser beams inside the crystal, which are two important points in three-level lasers. We have validated our numerical model by building an efficient cw Yb:S-FAP (ytterbium:strontium-fluoroapatite) laser emitting at 985 nm and pumped at 899 nm by a Ti:sapphire laser. Our model can be used to define the parameters that optimize the laser output power at 985 nm, such as the relative sizes of the pump and laser beams, the optimum output coupler, or characteristics of the crystal (length, Yb concentration). By adapting this model to diode pumping, we have established the conditions to obtain cw, efficient laser operation at 985 nm of an Yb:S-FAP crystal pumped by a standard 1 × 100-µm² laser diode.
© 2005 Optical Society of America
Sylvie Yiou, François Balembois, and Patrick Georges, "Numerical modeling of a continuous-wave Yb-doped bulk crystal laser emitting on a three-level laser transition near 980 nm," J. Opt. Soc. Am. B 22, 572-581 (2005)