Transient numerical simulation of the effect of dielectric particle contaminant on fused silica in high-power laser system

Abstract

Particle contaminant-induced laser damage of optical components limits the outpower of high-power laser facility. Fused silica particles from damaged fused silica optical components can cause laser damage to optical elements. In this article, the influence of fused silica particles on fused silica surfaces is investigated. The Maxwell equation and free electron production rate equation are coupled. The results show that although the particles create an electric field-enhancing effect inside the component, the particles are still the first to be damaged because their free electron density is greater than the free electron density of the substrate. When the laser is incident forward, the peak of the free electron density curve of the particle and the substrate is proportional to the particle size. On the contrary, When the laser is incident from the back, as the particle size increases, the peak value of the free electron density curve first increases and then decreases. The shortening of the separation distance between particles significantly increases the free electron density inside the substrate.