Subpicosecond laser breakdown in optical thin films

Experimental and theoretical progress on subpicosecond laser pulse breakdown in dielectric films is reviewed. The single pulse threshold fluences can be related to fundamental material properties and scaling laws with respect to pulse duration and material bandgap are discussed. Multiple pulse thresholds are controlled by native and laser-induced defects. A phenomenological model is introduced that describes the accumulation and relaxation of such defects. The model is able to explain the experiments and can be used to assess relevant defect parameters. Experimental results are presented that exemplify how the ambient atmosphere affects the multiple pulse laser damage thresholds.