Thin layer surface resonators: a new spectroscopic tool for probing dielectric film structure and properties

摘要

Theoretical aspects of surface resonances are discussed, to-gether with the manufacture of silver based thiun film resonators and their application to studying both structural and mass distribution characteristics of biological membranes. The discussion focuses on a recently developed variant of surface plamson resonance (SPR) spectroscopy that involves copling of plasmon resonances in a thin metal film and waveguide modes in a dielectric overcoating. This new technique, referred to as coupled plasmon-waveguide resonance (CPWR) spectrocopy, combines a gratly enhanced sensitivity (due to increased electromagnetic field intensities at the dielectric surface) and spectral resolution (due to de-creased resonance line widths), with the ability to measure directly anisotropies in refractive index and optical absorption coeffieicnt in a dielectric film adsorbed onto the surface of the overcoatiing. The technique has been applied to the study of hipid film membranes and mebrane protins, important in biological processes.