High-sensitive plasmonic multilayer SiO${}_2$/VO${}_2$ metamaterial sensor

This paper presents a plasmonic metamaterial sensor utilizing an I-shaped gold resonator. The sensor is simulated using the finite-element method (FEM) to detect gas and liquid (ethanol solutions) in the infrared wavelength range of 0.5-2.5 µm. The sensor structure consists of three layers, with a VO${}_2$ substrate sandwiched between a bottom SiO${}_2$ substrate and a top gold resonator. The design exhibits distinct absorption characteristics across the range of 0.5-2.5 µm, tailored for different gas and liquid sensing applications. A comparison is made between the two states of VO${}_2$ to investigate the sensitivity of the device. Geometrical parameters, including height and width, are optimized, and three types of comparisons are conducted. First, a sensitivity comparison is made between this work and previously published research. Second, a Quality factor and Figure of Merit comparison is performed. Finally, a sensitivity comparison is made between different sensing techniques and the technique employed in this work. After optimizing the design parameters, the device demonstrates the highest detection sensitivity for gas and ethanol solutions, yielding results of 2800 (nm/RIU) and 2600 (nm/RIU), respectively. The proposed I-shaped gold-based metamaterial exhibits the potential to be utilized as a lab-on-chip biosensor.