Specific features of linear and nonlinear optical responses of chalcogenide glasses in the As-S-Se and As-Se-Te systems

Transmission and reflection spectra of samples of chalcogenide glasses in the As-S-Se and As-Se-Te systems have been measured in the wavelength range of 0.4–2.5 μm. Spectral dependences of the single-photon absorption coefficient and refractive index are obtained, the parameters characterizing the fundamental absorption edge are determined, and the Kerr constant in the low-frequency limit is calculated. Based on the obtained results and the data in the literature, dispersion curves are plotted for the Kerr constants of As₂S₃ and As₂Se₃ glasses near the absorption edge.