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