Ultrafast pump and probe investigations on the interaction of femtosecond laser pulses with glass

The change of the matrix structure of glass is investigated during and after irradiation with ultrashort pulsed laser radiation (100 fs < tp; < 3 ps) at the wavelength λ = 810 nm. The dynamics of the plasma expansion and the stress formations are visualized by time-resolved Normarski-photography. Optical microscopy visualizes the structural changes in glass. The spatial stress distribution and the refractive index change are shown in the time range 100 fs < t < 120 ns. The ionization state of atoms and/or the formation of color centers has been investigated by transient absorption spectroscopy (TAS) in the time regime 100 fs < t < 120 ns. The temporal change of the spectra shows different regimes, which can be explained by the electron and phonon relaxation.