In present analysis a semiconductor-based surface plasmon resonance structure using Gr-IV materials (Silicon and
Germanium) has been analyzed in spectral interrogation mode which can be used for efficient environmental monitoring
and Infrared (IR) gas-sensing purposes. The Silicon-Germanium (Si-Ge) combination structure is able to confine an
extremely high evanescent field in the sensing region due to their extraordinary high refractive indices (RI). Higher
concentration of optical field in the sensing area provides enhanced spectral sensitivity for infrared gas-sensing. Better
detection accuracy and adequate dynamic range are other additional advantages offered by such semiconductor-based
surface plasmon resonance (SPR) configurations. Analysis of the SPR structure has also been carried out in terms of
detection accuracy, figure of merit and Q-factor of the gas-sensor.
A prism coupler-based nano-plasmonic sensor consisting of a high refractive index (RI) prism (2S2G-prism, LASF9-prism), gold (Au) metal film, and different amino acids as the dielectric sample is used for sensing in attenuated total internal reflection mode. An additional semiconductor (silicon) nano-layer over the gold surface has been used for increasing the stability and sensitivity of the surface plasmon resonance sensor. A comparative analysis of performance of the nano-plasmonic sensors in the spectral regime using these two high RI prism materials with an additional semiconductor nano-layer has been presented. The sensing performance of the proposed nano-plasmonic sensors in terms of evanescent field enhancement, spectral sensitivity, detection accuracy, figure of merit, and Q-factor with different amino acid samples has been discussed along with supporting theoretical simulations in a MATLAB® environment.