Numerical simulations of laser/defect-induced absorption in SiO 2

Abstract

We have performed simulations of laser energy deposit in sub-micrometric spherical defects and the surrounding fused silica. We have studied crater generation produced by the absorber explosion with a 2D/3D Lagrange-Euler code taking into account crack formation and propagation in the brittle material. The comparison of the 2D simulations with experiment shows quite good agreement for shallow defects (depth < 2 µm). We have observed experimentally that the explosion of deeper absorbers results in a more complex crater morphology. Therefore we have begun performing 3D simulations in order to reproduce these features.Depending on the defect depth, the cracks may not reach the surface and a crater doesn't appear. Nevertheless, those cracks or pre-existing cracks can contribute to efficient electric field enhancement and breakdown on the surface. Different types of cracks (size, inclination, filled with a material or not) were investigated and the 2D or 3D electromagnetic field distributions were computed using a finite element code.

Numerical simulation of the modulation to incident laser by the repaired damage site in a fused silica subsurface

“…[3] Bonneau et al has performed twodimensional (2D) simulation of intensity distribution around the plannar and conical cracks by using the DELPOR code and HESIONE code. [9] Hua et al simulated the light intensity distribution in the vicinity of 3D Hertzian conical scratches on fused silica subsurface. [10] Nevertheless, these simulations focus on the given kinds of cracks which are plannar and conical cracks.…”

Effect of fused silica subsurface defect site density on light intensification

“…Génin et al [11] numerically simulated the intensity distribution using TEMPEST code around the planar and conical cracks. Bonneau et al [12] performed a two-dimensional (2D) simulation of intensity distribution around the planar and conical cracks by using DELPOR code and HESIONE code. Hua et al [13] simulated the light intensity distribution in the vicinity of three dimensional Hertzian conical pits on fused silica subsurface.…”

Laser-Induced Thermal Damage to K9 Glass on Finite Element Method

“…When the laser irradiation on optical materials, which absorb the laser energy and make the temperature and stress change. Because of the complexity of the material structure and variable temperature conditions, rely on the traditional analytic method to accurately determine the temperature field and thermal stress field is often not possible, finite difference method for addressing the problem of irregular shape the structure of the accuracy is not high, so the finite element method become a convenient and effective tool to solve it [4] . In this paper, we put the time distribution feature of the gaussian pulse laser as a heat source to load, heat conduction equation in cylindrical coordinates, through the finite element discretization, unit analysis and general analysis, finite element calculation formula.…”