Optical components based on arsenic sulfide (As2S3) glasses have been widely used for infrared optical applications since the development of these glasses in the late 1960's. During the past several years, As2S3 and related chalcogenide glasses have found use in a variety of novel optical components based on bulk, film, or fiber forms. This three year, multidisciplinary research project will examine the fundamental structural and optical property differences that exist between bulk arsenic-sulfur-selenium glasses and the as-deposited glass films as would be used in the multilayer thin film waveguides found in integrated optical device systems . The project aims to identify the underlying chemical and structural differences in the glasses and assess the ramifications of such differences on the optical performance of the resulting waveguide. The structural and compositional (including stoichiometric and bonding variations) differences in glass film versus parent bulk glass, and how these differences relate to processing conditions (melting versus vapor deposition) will be examined. Surface and bulk glass structural tools such as XPS, EXAFS and selected spectroscopic techniques will be used to identify differences in structural features. Film deposition conditions, which dictate how structural units form and assemble into stable and metastable configurations, will be characterized by Raman spectroscopy and other techniques. The identity of key structural units in bulk and film forms of chalcogenide glasses and the role that relative differences in unit concentrations play on physical properties (including linear and nonlinear optical) will be identified. The stability of as-deposited film structure and properties and the role of intrinsic and extrinsic glass defects on the glass structure, optical behavior, and stability will be determined. Finally, the structural modification that occurs in glass films with light interaction and the impact on glass structure and ultimate device optical performance will be investigated. %%% The objective of this project is to assess what variation in composition, structure, physical properties, and optical performance result when bulk chalcogenide glasses undergo thin film processing procedures commonly used in the production of multilayer thin film waveguides used in integrated optical device systems. This project will be performed by a Focussed Research Group consisting of an international, multidisciplinary team of researchers from the Center for Research and Education on Optics and Lasers (CREOL) and the Advanced Materials Processing and Analysis Center (AMPAC) at the University of Central Florida, the Center for Optics, Photonics and Lasers at the Universite de Laval (Quebec, Canada), and the Institut de Chimie de la Matiere Condensee Bordeaux of the Centre National de la Recherche Scientifique (Bordeaux, France). These groups have and on-going relationship that will facilitate the faculty and student exchange part of the project, further broadening the project's impact on technological and educational programs at the participating institutions. ***
