Effect of pulse energy and numbers on fused silica surface by ultraviolet laser pulses at 355nm in vacuum

摘要

High-purity fused silica irradiated by UV laser in vacuum with different laser pulse parameters were studied experimentally. The defects induced by UV laser are investigated by UV absorption, fluorescence spectra and the structural modifications in the glass matrix are characterized by Raman spectra. Results show that, for laser fluence below the laser-induced damage threshold (LIDT), irradiation results in the formation of an absorption band and four defect-related fluorescence (FL) bands, and the intensities of absorption band and FL bands were increased with laser power and/or number of laser pulses. The optical properties of these point defects were discussed in detail. Analyzed these spectra, it indicates that the presence of different centers whose spectral features are modulated by structural disorder typical of the glass matrix.