Self-optimized resonator for optical pumping of solid-state lasers

We show that the proper use of a self-imaging confocal cavity can be a simple way to optimize the efficiency of optical pumping of solid-state lasers. In this type of resonator the transverse mode self-adjusts to fit the pumped volume optimally. Self-optimization of the mode size of a laser-diode pump Nd:YAG laser (54% slope efficiency) is demonstrated, and an intrinsic efficiency of 68% is measured.