Scaling of longitudinally diode-pumped self-frequency-doubling Nd:YCOB lasers

We report the scaling of a new self-frequency-doubling laser, based on the crystal Nd/sup 3+/:YCa/sub 4/O(BO/sub 3/)/sub 3/, to higher powers. The power scaling is achieved by diode pumping using a novel technology of combining the output of up to four high-brightness laser diodes. Spectroscopic, thermo-mechanical, and laser properties are investigated for use in designing high-power self-frequency-doubling lasers. Using a method of angular-multiplexing individual laser diodes for pumping, we demonstrate output powers of more than 1.9 W of fundamental (1060 nm) radiation and 245 mW at the second harmonic. Experimental investigation rendered a thermal stress resistance figure-of-merit for this material to be between 210-280 W/m.