Quintuple grids plasmonic refractive index sensor for organic gas sensing application

Abstract

In this article, an optical refractive index (RI) nanosensor has been presented. The layout is arranged in a metal–insulator-metal (MIM) waveguide configuration with gold being the plasmonic metal. The waveguides are coupled with quintuple grids resonant cavity where the grids are uneven in length. The transmission spectral profile of the schematic is numerically analyzed employing the two-dimensional Finite Element Method (FEM) within the mid-infrared region (MIR). Moreover, the key structural parameters are optimized individually to realize the maximum performance of the schematic. The most optimal structure displays a high sensitivity of 4737.87 nm/RIU and a FOM of 9.37. Furthermore, the structure can be suitably used in applications such as sensing organic gas vapors and temperature. Due to the practicality of the applications and the simplicity of the schematic along with the higher longevity provided by gold, this device can replace complex structures effectively.

Keywords

• Surface plasmon polaritons
• Fano resonance
• Refractive index sensor
• Organic gas sensor