Three-dimensional particle-in-cell simulations of intense few-cycle pulse, multilayer interference coating interactions

The development of next-generation laser optics can be guided by studies looking to improve the laser-induced damage threshold of highly-reflective interference coatings. We model intense few-cycle pulses interacting with multilayer HfO2/SiO2 dielectric interference coatings using fully three-dimensional particle-in-cell simulations to which we have added a Keldysh model for photoionization and a dielectric model to include refractive properties of the materials. We explore the reflection, transmission, and absorption of the laser pulses. We use the predicted excited electron density and energy density to estimate damage thresholds for these optics. This research was funded by DOE STTR grant no. DE-SC0019900.