UV laser-induced damage tolerance measurements of CsB3O5 crystals and its application for UV light generation

Cesium triborate, CsB3O5 (CBO), is an excellent nonlinear optical crystal for ultraviolet light generation. CBO crystals can be grown by top seeded solution growth from self flux solutions. The growth of large-size crystal is difficult because of the multi-nucleation and dissolution of seed during growth. These problems have been avoided and large size crystals (159.2 g) of size 50 × 45 × 45 mm3 (a × b × c) have been grown. The bulk laser-induced damage threshold (LIDT) of CBO was determined using an 1-on-1 technique by the third-harmonic (355 nm) light of longitudinal single-mode Q-switch Nd:YAG laser. The bulk LIDT was found to be two times that of fused quartz for a 6 ns pulse. The as-grown CBO crystal has been used to generate the highest ever reported third-harmonic power of 103 W for the case of a single-pass frequency-conversion system using a high-power Nd:YAG laser.