A series of fused silica surface have been created by reaction ion etching to determine the effect of the contamination
level on surface state and optical performance of the optics. The results show that both impurity elements contamination
and scratches of fused silica surface can be removed dramatically during RIE process. The laser induced damage
threshold is raised by 37.6% when the polishing layer is removed for a thickness of 6μm, and the laser weak absorption
doesn’t increase obviously. The results can provide technique support for improving laser induced damage performance
of fused silica.
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.