Diode-End-Pumped 15-W Nd:YAG Laser

We describe the design and performance of a 15-W output power, diode-pumped cw Nd:YAG laser. The device is end-pumped using four 10-W cw diode bars, and achieves a coupling efficiency of 80% into a 3-mm mode volume. While operating on several transverse modes the laser has a threshold of 3 W, an optical slope efficiency of 60% and an overall electrical efficiency of 10.5%. The laser produces average powers of 10 W and peak powers of 5.8 kW under Q-switched operation. Thermally-induced higher-order spherical aberration of 1.3 μm lmits fundamental mode operation to approximately 6 W.