A new method of sensing small refractive index changes of a liquid analyte using the effect of surface plasmon resonance (SPR) at different angles of incidence is presented. The method is based on detection of the phase shift induced by SPR in the Kretschmann configuration with an SPR structure comprising an SF10 glass prism, a gold coated SF10 slide with chromium adhesion layer, and an analyte (aqueous solutions of ethanol). First, the theoretical modeling of the phase shift at different angles of incidence induced by SPR is performed using the material dispersion characteristics. The phase shift at different angles of incidence is evaluated at a specific wavelength as a function of the analyte parameter and sensitivity is specified. Second, the theoretical modeling is accompanied by an experiment utilizing a polarimetry setup to detect the spectral phase shift induced by SPR. In addition, the phase shift is measured at a specific wavelength as a function of the analyte parameter, and the sensitivity is determined for different angles of incidence.
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