Micro-photoluminescence study on defects induced by ion microbeam in silica glass

We have evaluated the irradiation effects by ion microbeam on silica glass for various ion species by means of a micro-photoluminescence technique. Defect generation and refractive index change were observed for silica at the area of 10 μm × 50 μm scanned by ion microbeam of H⁺, He⁺, N⁴⁺, C⁴⁺, O⁴⁺, and Si⁵⁺ with energy from 1.7 to 18 MeV. The μ-PL spectroscopy measurements were performed along the side surface perpendicular to the microbeam irradiated surface. Based on the comparison with a result of SRIM (stopping and range of ions in matter) simulation, the defect generation mechanism was discussed in terms of the energy deposition processes due to electronic and nuclear stopping powers. We conclude that the electronic stopping power is responsible for the defect generation at the track of ions. The effect of the nuclear stopping power is also not negligibly small at the end of range.