Growth of laser damage in fused silica and CaF₂ under 263 nm laser irradiation

This study examined the growth of the laser-damage performance in optical components under the fourth harmonic of Nd:glass laser irradiation (263 nm). The damage-growth threshold of the optical component was relatively low under 263 nm laser irradiation compared to 351 nm irradiation, owing to the higher energy level of 4 \(\omega \) $\omega$ photons, and depended on the material characteristics. The preliminary growth of laser damage in fused silica and CaF₂ under 263 nm laser irradiation is reported in this article. The damage growth coefficients of these two materials were obtained by continuously irradiating the optical components using a 263 nm laser with a pulse width of \(\tau = 5\) $\tau =5$ ns. The damage growth threshold of fused silica is lower than that of CaF₂ because of differences between the materials. The damage characteristics, including the damage morphology and bulk damage, were analyzed.