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.