Numerical modelling of light propagation in surface plasmon resonance sensor with liquid crystal

Abstract

The five-layer nanorod-mediated surface plasmon sensor with inhomogeneous liquid crystal layer was theoretically investigated. The reflectance as the function of the incident angle was calculated at different voltages applied to the liquid crystal (LC) for different analyte refractive indices. By changing the LC director orientation one can control the position of the reflective dips and choose the one that is the most sensitive to the analyte refractive index. At the chosen angle of incidence, the analyte refractive index can be found from the reflectance value. The director reorientation effect is stronger when the prism refractive index is between ordinary and extraordinary refractive indices of the LC. In this case, the voltage increase and the prism refractive index decrease have a similar effect on the reflectance features.

Keywords

• liquid crystal
• surface plasmon resonance
• sensor
• nanoparticles
• porous metal film