A new evaluation of Yb3+-doped crystals for laser applications

We develop a new model for the quasi-three-level laser. It deals with Gauss ian waves, takes into account the saturation of the pump, the stimulated em ission at the pump wavelength, the Variation of the pump and laser waists a long propagation (important for laser diode pumping) and the variation of t he laser intensity along propagation. The model is used to evaluate the mos t promising Yb3+-doped crystals: YAG, GdCOB, YCOB, YAB, C-FAP, S-FAP, KGdW, KYW, for CW longitudinally pumped lasers. Our evaluation differs from Delo ach and coworkers, devoted to e-switched oscillators or nanosecond-pulse am plifiers. KYW, KGdW, YAB and GdCOB are found to be the most efficient when the laser extracted power and the slope efficiency are considered. (C) 2001 Elsevier Science B.V. All rights reserved.