High-repetition-rate UV laser with CLBO and its reliability for long-term operation

Summary form only given. All-solid-state UV lasers have been in demand for various industrial and medical applications because of the convenient operation procedure and cost effectiveness as alternative to corrosive gas-based excimer laser. The performance of such lasers seems to depend on the capability and reliability of UV frequency converter. At this moment, CsLiB/sub 6/O/sub 10/ (CLBO) is the most effective nonlinear optical crystal to generate high-power fourth and fifth-harmonics of Nd:YAG laser. However, for high-repetition-rate, high-power UV operation, the surface damage of CLBO crystal often limits the long-term operation. One of the primary mechanisms proposed for the damage is thermo-mechanical damage due to absorption by polishing contaminants in the surface region. In a previous paper, it was reported that removal of residual polishing compounds on CLBO surfaces by ion beam etching increased laser damage durability. In this work, we have constructed all-solid-state UV laser by using the CLBO with this technique and improved its reliability.