3.5-W Q-switched 532-nm Nd:YAG laser pumped with fiber-coupled diode lasers

A diode-pumped laser with greater than 11 W of cw 1064-nm output power and 3.5 W of frequency-doubled average power at a 50-kHz pulse repetition frequency has been developed. A single Nd:YAG rod was pumped with the combined output of three fiber-coupled diode-laser arrays. Each pump laser was capable of 10 W of cw output power. The fiber output of each pump laser was first collimated and then focused with a single lens onto one end of a Nd:YAG rod. The resonator mirrors for the L-shaped cavity were selected such that thermal lensing in the laser crystal was mostly compensated. The 532-nm output beam quality factor (M(2)) was less than 1.5.