High power Nd:YAG spinning disk laser.

We report on a high power Nd:YAG spinning disk laser. The eight cm diameter disk generated 200 W CW output with 323 W of absorbed pump in a near diffraction-limited beam. The power conversion efficiency was 64%. The pulsed result, 5 ms pulses at 10 Hz PRF, was nearly identical to the CW result indicating good thermal management. Rotated at 1200-1800 RPM with He impingement cooling the disk temperature increased by only 17 °C reaching a maximum temperature of ~31 °C. The thermal dissipation per unit of output power was 0.61 watt of heat generated per watt of laser output, which is below the typical range of 0.8-1.1 for 808 nm diode pumped Nd:YAG lasers.