Contrasted fatigue behavior of laser-induced damage mechanisms in single layer ZrO₂ optical coating

The decrease of laser-induced damage threshold (LIDT) when exposed with high number of laser pulses is a well-known phenomenon in dielectrics. In the femtosecond regime this fatigue is usually attributed to the incubation of laser-induced lattice defects. In this work, a computational model is used to combine the data from time-resolved digital holographic microscopy measurements together with results of S-on-1 laser-induced damage threshold test in order to investigate fatigue of ZrO ₂ single layer coating. Two distinct damage modes were identified and shown to follow different fatigue behaviors: formation of catastrophic damage is highly nonlinear in time, while incubation of color-change mode appears to be linear in time.