SPR-leaky-mode spectroscopy with polymer films for optical chemosensors

摘要

Abstract: The optical reflectivity of multilayers consisting of a metal layer of about 50 nm and a dielectric layer in the thickness range of an optical waveguide gives rise to different resonances. In the metal layer the surface plasmon (SPR) may be excited while in the dielectric layer waveguide resonances can be observed, when the resonance conditions are fulfilled. Resonance spectra can be obtained by varying the angle of incidence with monochromatic light or by varying the wavelength at a constant angle of incidence. The evaluation of the resonance light or by varying the wavelength at a constant angle of incidence. The evaluation of the resonance spectra allows the determination of all the involved optical parameters of the multilayer like layer thicknesses and real and imaginary parts of the refractive indices. Using polymer films in the position of the dielectric films the whole set of interactions of thin polymer films with the surrounding environment. This makes the method interesting for optical sensor devices. Depending on the particular interest low price, compact and selective methods of monitoring in situ processes may be realized based on the combination of the SPR-leaky technique. !32