“…Compared to the conventional solid-state lasers, high output power can be obtained from a small volume of the laser medium. Among the numerous Yb-doped crystals used in the thin disk laser, Yb:YAG is the most fascinating as a high power diode-pumped laser gain media due to its small quantum defect between the pumping and the lasing photons resulting in low thermal loading, long radiative lifetime of the upper laser level, large absorption and emission band widths [3]. Also, YAG crystal offers excellent properties for high Yb 3+ doping concentration, which allows one to use a rather thin disk (thus to minimize thermal effects) without arranging for too many passes of the pump radiation.…”