Modelling the Surface Plasmon Spectra of an ITO Nanoribbon Grating Adjacent to a Liquid Crystal Layer

The reflection and transmission coefficients of an indium tin oxide (ITO) nanoribbon grating placed between a nematic liquid crystal (LC) layer and an isotropic dielectric medium are calculated in the infrared region. Reflection and transmission spectra in the range of 1–5 μm related to the surface plasmon excitation in the ITO nanoribbons are obtained. Dependence of the peak spectral position on the grating spacing, the ribbon aspect ratio, and the 2D electron concentration in the nanoribbons is studied. It is shown that director reorientation in the LC layer influences the plasmon spectra of the grating, enabling a control of both the reflection and transmission of the system. The data obtained with our model are compared to the results obtained using COMSOL software, giving the similar results.