Photo-induced effects in GeS2 glass and glass-ceramics stimulated by green and IR lasers

International audience; A transient effect induced by an irradiation treatment using a cw green (532 nm) laser or a microsecond pulsed CO2 laser at 10.6 μm was observed on the absorbance and on the refractive refractive index in the visible spectral range. We have found modifications of absorption and refractive index in visible range which relax and disappear after the power cut of irradiation. Two main mechanisms participate in the observed photo-induced effects: the polarization of trapping states within the energy band-gap should be due to pure electronic contribution and/or related to the phonon sub-system manifesting through electron-phonon interactions. The relaxation of the photo-induced changes, after switching off the laser treatment, is also studied.