  Recent progress in the development of high-power mid-IR laser sources and the
exciting laser driven physical phenomena associated with the irradiation of
solids via ultrashort laser pulses in that spectral region are aimed to
potentially create novel capabilities for material processing. In particularly,
the investigation of the underlying physical processes and the evaluation of
the optical breakdown threshold (OBT) following irradiation of bulk dielectric
materials with Mid-IR femtosecond (fs) pulses has been recently presented. In
this report, we will explore the conditions that generate sufficient carrier
excitation levels which leads to damage upon irradiated a dielectric material
(SiO2) coated with antireflection (AR) semiconducting films (Si) of variable
thickness with fs pulses. Simulation results demonstrate that the reflectivity
and transmissivity of the Si/SiO2 are thickness-dependent which can be employed
to modulate the damage threshold of the substrate. The study is to provide
innovative routes for selecting material sizes that can be used for
antireflection coatings and applications in the Mid-IR region.
