New optical materials of Ge-As-S AND As-S-Se glassy systems

Abstract

Nowadays chalcogenide glasses are well known as multifunctional materials with specific electrical and optical properties, for their potential applications in microelectronics and optoelectronics as ovonic devices, passive and active optical elements, components of the photonic structures and recording media of high density. Chalcogenide glasses (As-Se, As-S-Se, As-Sb-S, Ge-As-Se) are characterized by the wide region of glass formation, high glass transition temperatures (Tg=300400 0C) and thermal stability. These glasses are of considerable interest also due to high values of refractive index (n=2.42.65), high nonlinearities (n2=2.510-17 cm2 /W) for g-As15Ge35Se50, and optical transmission at 1.55 m, that makes them suitable for photonic applications. Chalcogenide glasses are sensitive to the external illumination and exhibit reversible and irreversible photoinduced effects. These effects are used for the fabrication of different registration media, diffractive structures, waveguides, photonic structures, and optical amplifiers. Arsenic chalcogenide films usually become darkened under light irradiation in the region of the fundamental absorption edge. The changes in the optical constants (absorption coefficient , optical band gap Eg, and refractive index n) of the investigated materials under ionization irradiation and heat treatment were evaluated.