Theoretical modelling and experimental investigations of the diode-pumped thin-disk Yb : YAG laser

The fundamental principles of the operation of a solid-state laser are presented for the case when the active element is a thin disk. An analytical model of this laser is developed. The model is used to calculate the influence of the various parameters on the operational efficiency of the laser. A detailed model is also developed for calculations relating to a specific laser design and this model takes account of the geometry of the active medium, of the diode pump configuration, and of the operating conditions. Experiments yielded a cw output power up to 350 W and an optical pumping efficiency of ~ 50% (the corresponding values obtained in this single-mode regime were approximately 100 W and 440%). These results were obtained below 0 °C for eight passes of the pump radiation through the active medium. At room temperature and for 16 passes the same parameters were several tens of watts and an efficiency up to 58%. These experimental results were in good agreement with the predictions of the theoretical model.