Pulse duration and band-gap scaling of the laser breakdown threshold fluence of oxide dielectrics were measured using various (TiO2, Ta2O5, HfO2, Al2O3, and SiO2) single layer thin films. The observed scaling with pulse duration was explained by an empirical model including multi-photon and avalanche ionization, and conduction band electron decay. The results suggest the formation of self-trapped excitons on a sub-ps time-scale, which can cause significant energy transfer to the lattice. At constant pulse duration, the band-gap scaling was found to be approximately linear. This linear scaling can be explained by the Keldysh photo-ionization theory and avalanche ionization in the flux-doubling approximation.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.