Temporal and spatial changes in the matrix of glasses (BK7 glass, fused silica, quartz) are investigated during and after irradiation by pulsed laser radiation (100 f(s) < t(p) < 3 ps) at the wavelength lambda = 800 nm using high-speed photography, transient absorption spectroscopy, and Nomarski-microscopy to visualize the changes of optical properties, plasma formation and expansion, stress formation, modification, and cracking. Depending on the excitation conditions the glasses exhibit different excitation and relaxation channels including various types of defect centers in the glass. Compared to laser irradiation with pulse durations t(p) in the nanosecond regime, when the glasses are heated within the irradiation zone for many nanoseconds resulting in an increase of the refractive index without cracking enabling the generation of photonic structures within the bulk, irradiation with pulse durations in the picosecond regime leads to cracking, thus enabling marking in the bulk and at the surface. (c) 2005 Elsevier B.V. All rights reserved.