Predictive growth model of LID: light intensification model

Abstract

General precursors and growth model of Laser Induced Damage (LID) have been the focus of research in fused silica material, such as polishing residues, fractures, and contaminations. Assuming the absorption due to trapped material and mechanical strength is the same across the surfaces, various studies have shown that the LID could be minimized by reducing the light field intensification of the layers upon the laser strikes. By revisiting the definition of non-ionising radiation damage, this paper presents the modelling work and simulation of light intensification of laser induced damage condition. Our contribution is to predict the LID growth that take into various factors, specifically on the light intensification problem. The light intensification problem is a function of the inter-layer or intra-layer micro-optical properties, such as transmittance and absorption coefficient of the material at micro- or sub-micro-meter range. The proposed model will first estimate the light propagation that convoluted with the multiply scattering light and subsequently the field intensification within the nodule dimension. This will allow us to evaluate the geometrical factor of the nodule effect over the intensification. The result show that the light intensification is higher whenever the backscattering and multiple scattering components are higher due to its interference with the incoming wave within its coherency.