Effect of multiple laser irradiations on silica at 1064 and 355 nm.

We analyze laser damage precursor evolution under multiple irradiations by changing test parameters such as shot number, wavelength, shot frequency, and test location (bulk or surface). The experimental data exhibit different behaviors under repetitive shots regarding the damage precursor densities and thresholds. The results provide new information for understanding the laser damage initiation process in silica. Furthermore, the data permit us to predict the lifetime of optical components under multiple irradiations.