Broadband surface plasmon resonance spectroscopy for determination of refractive-index dispersion of dielectric thin films

摘要

Here the authors report the spectral surface plasmon resonance (SPR) behavior of thin gold films covered with dielectric layers. With the SPR sensor angular dependence of the resonant wavelength and refractive-index (RI) sensitivity at a specific angle were measured by broadband absorption spectroscopy. By fitting the calculated SPR absorption spectrum to the experimental result, RI dispersion of a TiO_2-nanoparticle/polymer composite layer was obtained, which was compared with the ellipsometry data. The phase spectra of the sensor were calculated, and a large response of the phase to the solution RI was observed around the resonant wavelength.