High-average-power (15-W) 255-nm source based on second-harmonic generation of a copper laser master oscillator power...

We have generated 15 W of UV (255-nm) radiation with an optical conversion efficiency of 28% by frequency doubling the 510.6-nm output of a high-beam-quality, high-power copper laser system in cesium borate lithium (CLBO). We found that the superior performance of CLBO relative to beta-barium borate is attributable largely to the small UV absorption and wide temperature acceptance bandwidth of CLBO, which reduces thermal dephasing during high-power UV generation.