CO2 laser induced two-photon absorption detected by near-infrared lasers in As2Se2S glasses

Influence of CO2 pulsed microsecond laser on two-photon absorption (TPA) at wavelengths of Nd:YAG (1060 nm and 1320 nm) and Er glass lasers (1540 nm) for As2Se2S glasses was studied. Dependence of the TPA versus the photoinducing power densities at wavelength 9.2 mu m is studied. The highest values of the TPA beta coefficient were achieved for perpendicular polarizations between the pumping and probing laser beams. The obtained values of TPA coefficients indicate a possibility of using the As2Se2S glasses as optically-operated IR laser limiters in a wide spectral range. The substantial role of anharmonic electron-phonon subsystem is demonstrated.