Fig. 2

TDL concept a) Schematic illustration of one of the most typically used arrangement (to scale of a typical Yb:YAG TDL): multi-pass pumping and single-pass gain. The re-imaged pump beam after each disk pass can be thought of as multiple beams impingent on the disk with decreasing intensity at each bounce. A similar multi-pass arrangement can be made for the laser beam b) schematic side view of the disk (not to scale)