The laser diode array (LDA) pumped Yb:YAG thin disc laser with a 10 mm diameter and 300μm thickness crystal bonded to Cu heat sink by Indium soldering has been demonstrated. The doping concentration is 10 at. %.The temperature of Yb:YAG crystal was controlled by water-cooled system. The pump-beam radius was calculated by Monte-Carlo method. Considering mode matching
the angle between pump light and bundle was controlled under 120. The four-pass optical coupling system was well designed with two spherical imaging mirrors(Φ=30mm
R=50mm). When the incident power was 4.13W
a cw output power of 670mw at 1030nm has been obtained. The optical conversion efficiency was 16.2%.