Optical Properties of Composite Material: Chalcogenide Thin Films

Chalogenide glasses, with favorable properties like high linear and nonlinear refractive index, good transmittance in the infrared region, low phonon energy and photosensitivity make these glasses a potential candidate in lasers, amplifiers and high brightness sources for remote sensing applications. The present work deals with the linear and nonlinear optical properties of ternary (SeTe-Bi) and quaternary (Se-Te-Bi-Sn) chalcogenide thin films. In this thesis we have studied following chalcogenide glass systems.I. Se85-xTe15Bix (0 ≤ x ≤ 5)II.Se84-xTe15Bi1.0Snx (0 ≤ x ≤ 8)The bulk samples were prepared by using well known melt quenching technique. The thin films of bulk samples were deposited on glass substrate using thermal evaporation method. The amorphous nature of bulk samples and their corresponding thin films has been confirmed by using X-ray diffraction technique. The optical properties are determined using transmission and reflection spectra in the spectral range 400-2500 nm obtained from a double beam UV-Vis-NIR spectrophotometer. The linear refractive index and extinction coefficient has been evaluated using Swanepoel method.