Spectroscopic studies of thin film polymer laminates using raman spectroscopy and integrated optics

Abstract

Calculation of the optical field intensity distribution within a multilayered asymmetric slab waveguide indicates that specific modes can be selected where a maximum optical field intensity exists either within one of the component layers or at the interface between two adjacent layers. Corresponding Raman measurements have been obtained from multilayered polymer waveguides composed of thin films (∼1 μm) of poly(vinyl alcohol) (PVA), polystyrene (PS), and poly(methyl methacrylate) (PMMA). The ability to observe Raman scattering from submicron films results because of the high optical field intensity which occurs within the films and the increased scattering volume afforded by integrated optical techniques. Results suggest that, in addition to studying the polymer/polymer interface, this technique provides a nondestructive method for investigating coatings using in this case the penetration of the evanescent tail of a wave guided in a PVA overlayer to obtain Raman scattering from the thin underlying film. © 1981 American Chemical Society.