Tunable metasurface refractive index plasmonic nano-sensor utilizing an ITO thin layer in the near-infrared region

In this paper, a refractive index plasmonic nano-sensor with an array of metallic nano-rods has been designed in the near-infrared region. The tunable sensor is based on a perfect absorber, and an indium tin oxide (ITO) layer has been utilized as an active metasurface to improve sensor performance. By applying the voltage to the ITO layer, a perfect absorption has been obtained. Also, the sensitivity rises from 625 to 1125 nm/RIU (refractive index unit), and the figure of merit is 10 times higher. Moreover, the sensor application in the fields of medicine and hematology has been shown. The proposed sensor can be used to diagnose and determine anemia and malaria parasites.