Transient interference implications on the subpicosecond laser damage of multidielectrics

摘要

Laser-induced damage in optical thin films with subpicosecond pulses is investigated. A model dedicated to optical interference coatings and based on the rate equation for free electron generation is introduced. It takes into account the transient interference effects induced by changes in the dielectric function during the laser pulse and its feedback effect on the electron density distribution in the multilayer stack. Simulations are compared to experiments on HfO_2 and Ta2O_5 films with pulses ranging from 45 fs to 1 ps. It is shown that this approach can improve the interpretation of femtosecond and picosecond laser induced damage in thin films.