The application of silicon grating-enabled nanostructure for refractive index sensing in the near-infrared region is reported in this work utilizing surface plasmon resonance (SPR) phenomena. This grating helps in launching the plasmon modes efficiently towards the flat metal film deposited with a thin Al2O3 layer. Numerical simulation is performed based on rigorous coupled-wave analysis (RCWA) method using wavelength interrogation with a fixed incidence angle. The normal incidence light is used which can be helpful for its integration with optical fiber. The proposed structure has shown sensitive (with a sensitivity value of 1000 nm/RIU for analyte refractive index 1.32-1.33) and precise sensing behavior (average quality factor value of 650 RIU-1). Further analysis is extended toward the measurement of hemoglobin concentration in blood and possibility of gaseous sensing application (with high quality factor value of 2000 RIU-1) using the proposed structure. The performance analysis is presented in terms of well defined parameters of sensitivity and quality factor.
展开▼
