Time-resolved spectroscopic investigation of emission observed during damage in the bulk of fused silica and DKDP crystals

We have investigated the flash of light that accompanies laser damage using time-resolved spectroscopy. Damage events were initiated in the bulk of both fused silica and DKDP crystals with 355-nm 3-ns pulsed radiation. Spectra from the accompanying flash were recorded in the 200 - 500 ran wavelength range with 5-ns temporal resolution, Ten ns following damage initiation, the spectra were found to be roughly blackbody with temperatures on the order of 5000 K to 7000 K, depending on the material studied and excitation energy used, The observed temperatures and cooling rates can be related to the size and electron density of the plasma "fireball" that initiates the damage event.