Power dependence of defect formation in SiO2 glass by F2 laser irradiation

Abstract

The dependence of defect formation in a high-purity synthetic SiO 2 glass on F 2 laser power was studied. Above the threshold value of ∼10 mJ cm −2 pulse −1 (∼0.5 MW cm −2 ), the concentration of the laser-induced E ′ center created by the dissociation of Si–O–Si bond increased as a function of the F 2 laser power squared. The quantum yield of the E ′ center formed by the high-power F 2 laser irradiation was ∼3 orders of magnitude larger than that formed via two-photon absorption processes of KrF or ArF laser pulses. This strongly suggests that irradiating with the high-power F 2 laser creates the E ′ center via two-step absorption processes.