Laser-induced defects in fused silica by UV laser irradiation

The structure of fused silica with irradiation of the third harmonic of the Nd:YAG laser was investigated by Fourier transform infrared, Raman and Photoluminescence spectroscopy. Some variation in the Si/O stoichiometry of silica in the ablated spot was induced. The primary defect species are oxygen deficient centers and oxygen interstitials. The frequency shift of the Si–O–Si vibration proves that the central force constant between oxygen and silicon atoms, and the band angle of Si–O–Si increases in the UV-laser ablation spot. Small silicon clusters within SiOx appear to be a possible explanation for the 564 nm Fluorescence peak, and the 181 cm−1 Raman peak.