Irradiation effects on silica glass by ion microbeam for fabrication of optical elements

Irradiation of ion microbeam can induce a local refractive index change in silica glass. We have evaluated the changes in electronic structures of microbeam-irradiated silica glass by means of micro-photoluminescence and phase microscope measurements. Attention should be paid to the energy deposition processes by both electronic and nuclear stopping powers to control the depth distribution of refractive index changes. Also, a chemical effect induced by ion species such as protons at the projected range was also discussed.