Experimental study on ns pulsed laser induced damage in K9 glass

Experiment system to measure the damage thresholds of K9 glass irradiated by ns pulsed laser is established. Strong attention is paid to the method to detect the precusor of the damage. The sharp decrease of transmissivity or generation of scattered light are assumed to be the damage precursor, and thereby damage threshold is measured to be 18mJ or 1015W/m2, and the dependence of transmissivity on incident energy is presented. From the experiment result, it is found that avalanche ionization and self-focusing effect dominate the damage process in transparent dielectric.