Chalcogenide glasses contain one or more chalcogen element (Se, S, Te) which produces covalent bonds with the network formers like As, Sb, Ge, etc. Because of the high atomic masses and hence the low phonon energies in these elements, the transmission range extends into infrared region making it a suitable candidate for many applications in medical imaging, telecommunication, bio-sensing, infrared waveguides, optical fibers [1-4]. These materials appear a continuous alteration in many physical properties with alteration in chemical composition [5]. Many investigations of the electrical properties [6, 7], photo-conductivity [8], glass formation [9], study of structure [10] and analysis of crystallization kinetics [11-13] of the glassy (As–Se–Sb) system have been made. To our knowledge, less detailed investigations have been performed on their optical properties. In addition, more efforts have been carried out to develop the mathematical formulation describing both the reflectance and the transmittance of different optical systems