CHALCOGENIDE GLASSES: STRUCTURAL AND OPTICAL PROPERTIES

Abstract

Structural properties of chalcogenide glasses mainly on the example of binary As-S(Se) and Ge-S(Se) systems and ternary Ge-As-S(Se) systems, structural models, parameters of short range order of glasses obtained using diffraction methods, EXAFS and Raman spectroscopy are considered. Raman spectra of binary As-S(Se) and Ge-S(Se) systems and ternary Ge-As-S(Se) systems, structural models that are used for interpretation of Raman spectroscopy results are considered. Optical properties of chalcogenide glasses and optical absorption edge in binary and multicomponent systems are discussed. The refractive index and its wavelength dependence, other optical properties are among important parameters that determine the suitability of materials as optical media. Refractive and absorption indexes, optical band gap of chalcogenide glasses can be changed by doping of different elements. The results suggest a combined effect of chemical ordering and topological in such glasses (parameters dependence on average coordination number, composition, nanophase separation, etc.). Importance of study of interrelation of structural and physico- chemical properties is stated. As frequently pointed out by various researchers, chalcogenide glasses are promising materials for various applications because they are transparent over a wide range of wavelengths in the infrared region, they possess high linear and non-linear refractive indices, number of photoinduced effects, low phonon energies and are easy to fabricate. Applications of chalcogenide glasses cover wide range, among them: IR optics, recording and storage of information, xerography, thermoplastic and holographic media, inorganic resists, optical filters, diffraction optical elements, non-linear elements, fiber and integrated optics, etc. Composition-structure-properties correlations are convenient to tailor the physical, optical and other properties of chalcogenide glasses and provide an important reference for the further development of new chalcogenide glasses taking into account their possible applications.