A passively mode-locked composite thin disk Yb:YAG laser

Summary form only given. High power diode pumped mode-locked lasers are assuming increasing importance as pump sources for nonlinear optical processes and materials processing and surface modification. One of the more promising materials for high power operation is Yb:YAG because of its low quantum defect and absence of excited state absorption. The thin disk geometry has been shown to be highly effective for Yb:YAG and has proved to be popular and successful in recent years. Although the thin disk geometry ensures longitudinal extraction of heat, the conventional thin disk can still suffer from thermal lensing due to deformation of the disk. We have investigated the use of a composite Yb:YAG thin disk in which the very thin (approximately 200 /spl mu/m) absorbing part of the disk is bonded to a thicker undoped piece of YAG. This provides added design flexibility and reduced the need to incorporate compensation for significant thermal lensing into the cavity design.