Raman and Infrared Spectroscopy of Layered Structures

Abstract

Recent advances in Raman and infrared spectroscopy of thin films have led to new and better ways to probe layered structures of dielectrics, that is, organic and inorganic layers, perhaps even including metals. The characterization of specific groups present, their packing and orientation, and interfacial interactions, can many times be done from the observed spectra. Thin layers, however, present a problem of sensitivity because of the small number of absorbing species present and hence, a low signal to noise ratio. Various optical techniques have been developed to enhance the optical fields at a specific interface or in a specific thin film layer. Some of these techniques and results to be discussed are infrared absorption at glancing angles, guided optical waves using integrated optical structures, and surface electromagnetic waves, such as surface plasmons.