13 research outputs found
Numerical modelling of light propagation in surface plasmon resonance sensor with liquid crystal
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.Comment: 10 pages, 10 figures, 1 tabl
Surface plasmon absorption in MoS2 and graphene-MoS2 micro-gratings and the impact of a liquid crystal substrate
The absorption coefficients of a far-infrared wave are calculated at normal incidence for MoS2 and graphene-MoS2 micro-ribbon gratings placed between a nematic LC and an isotropic dielectric medium. Maxima in the absorption spectra, which are related to the excitation of the surface plasmons in micro-ribbons of these gratings, are observed. The spectral position of absorption maxima depends on the grating spacing, micro-ribbon width, and conductivity of the ribbons. The impact of the 2D electron concentration of the MoS2 ribbons on the plasmon bands is different for a MoS2-grating versus a graphene-MoS2 grating. The influence of the LC orientational state on the absorption spectra of the gratings enables the manipulation of the absorption peak magnitude