Infuence of crystallinity on the bulk laser-induced damage threshold and absorption of laser light in CsLiB6O10 crystals

The relationships among the bulk laser-induced damage threshold (LIDT), dislocation density and absorption of laser light in CsLiB6O10 (CLBO) were investigated. A newly developed synthesis process allows the growth of CLBO crystals with a LIDT of 2.5-fold higher than that grown by the conventional top-seeded solution growth (TSSG) technique. High-quality CLBO possesses lower dislocation density (6.6 x 10(3)/cm(2)) than conventional CLBO (similar to 15.0 x 10(3)/cm(2)). The absorption of laser light in CLBO was characterized by measuring the temperature increase on the crystal output surface during the generation of fourth-harmonic (@266 nm) light of Nd:YAG lasers. At a UV power of 5 W, the maximum temperature increase was 6 degreesC for high-quality CLBO, which was similar to 30% lower than that generated on conventional CLBO crystal. Thus, the reduction of dislocation density can suppress the absorption of laser light, which helps to enhance the resistance of CLBO against laser induced damage and alleviate thermal dephasing during the high-power generation of UV light.