Simulations of laser damage of SiO2 induced by a spherical inclusion

The purpose of this paper is to present the effect of a spherical inclusion in SiO 2 under pulsed laser irradiation. The 3D electromagnetic field distribution (E, B) in the inclusion and the SiO 2 bulk is calculated using the Mie theory extended to radially inhomogeneous media. The effects of electric field enhancement can be investigated for any size and any type (metallic or dielectric) of inclusion. This E-field enhancement may lead to direct breakdown of SiO 2 . The laser energy coupled with the inclusion and the host material is computed with the numerical code DELPOR along the laser duration. DELPOR is a 1D hydrodynamic code used for spherical geometry taking into account the laser solid- to-plasma interaction, thermal diffusion and phase transitions. During the laser pulse, the 1D hydrodynamic calculation is coupled with a 3D Lagrangian-Eulerian code to investigate the mechanical effects involved in the blow-up of the inclusion near the SiO 2 slab surface. For a set of experimental conditions, we attempt to determine the role of mechanical effects and E-field enhancement. Our ultimate goal is to predict laser damage morphology as a function of the physical and geometrical parameters (inclusion type, size and depth) of the inclusion and to compare it with experimental data.