Laser irradiation induced structural relaxation in the densified SiO2glass and SiO2thin film

Abstract
Laser irradiation induced structural relaxation in the densified SiO2 glass and SiO2 thin film has been probed by collinear photothermal deflection spectroscopy (PDS). Decreasing of optical absorption with the irradiation of Ar+ laser beam was observed in the densified SiO2 glass and SiO2 thin film. The structural relaxation is associated with the reactivation and recombination of localized defects which can be well described by the proposed relaxation function of φ(t) = (1 + at)−b. Distribution of relaxation times of the densified glass is broader than that of thin film.