<title>Analysis of the nonlinear mechanisms of light absorption in transparent materials under the ultrashort pulse laser action</title>

Abstract

The nonlinear absorption mechanisms in transparent materials under ultrashort laser pulses irradiation are considered theoretically. Nitride semiconductor, sapphire and others transparent dielectrics was investigated. The ablation threshold for theses materials is in multi-TW/cm² range. The model is used based on the tunneling absorption under the irradiation by high intensity ultrashort pulses in terms of theory of ionization of solid in a field of strong electromagnetic wave. Sartisfactory explanation is found of the influence of the material energy bandgap on the laser ablation threshold.