Effects of impurities (Fe, Ce, Cu, Ca) on electronic and optical properties in fused silica: a first-principles calculation

As a critical optical material in inertial confinement fusion (ICF), fused silica can be damaged by ultravioletlaser, which reduces its laser load capacity. The impurities existing on the fused silica surface can significantly reduce the laser damage threshold (LIDT) of fused silica. However, most of the theoretical research focus on the point defects, and few researchers systematically study the impact of impurities on optical absorption and LIDT of fused silica. Hence, in this paper, the impact of four typical impurities (Fe, Ce, Cu, Ca) on the electronic structures and optical properties of fused silica are studied by first-principles calculations. It is found that impurities can introduce defect states into the electronic structure of fused silica and enhance optical absorption in the visible-to-UV range, leading to laser damage and lower LIDT. Moreover, we find that the Ce atom with higher valency can cause stronger absorption of fused silica at UV range. Our work can provide theoretical support for the study of ultraviolet-laser damage of fused silica.