Photostructural defects resulting from exposure to intense near-infrared fs radiation was studied in three a-SiO2 glasses with various impurity levels. The photo-induced defects were studied by UV absorption spectroscopy and were correlated to the structural modifications in the glass matrix through Raman spectroscopy. Information in the dynamics of the defect generation was revealed by the small photon energy of IR femtosecond laser radiation.

Laser-Induced Defects in Fused Silica by Femtosecond IR Irradiation. A.Zoubir, C.Rivero, R.Grodsky, K.Richardson, M.Richardson, T.Cardinal, M.Couzi: Physical Review B, 2006, 73[22], 224117 (5pp)