IR laser induced spectral kinetics of AgGaGe3Se8:Cu chalcogenide crystals

The possibility to operate by optical spectra near the absorption edge gap was discovered for the AgGaGe3Se8:Cu semiconducting chalcogenide crystals under influence of microsecond CO2 laser with pulse energy 60 mJ operating at wavelength 10.6 μm. An occurrence of substantial photoinduced optical density was observed at wavelengths in the spectral range of 610-620 nm. Introducing of Cu ions leads to substantial spectral asymmetry in the observed spectra. The process achieves its maximum value after the 80-120 s of CO2 laser treatment and relaxes with almost irreversible changes after the same time. The contribution of thermo heating did not exceed 5-6%. Only the irreversible changes of the sample's surface topography were observed during the CO2 laser treatment, which do not influence the treatment. So the surface states do not play a principal role and the effect is prevailingly originated from the. The observed effect may be used for control of the CO2 laser power density.