Trapped Multimodal Resonance in Magnetic Field Enhancement and Sensitive THz Plasmon Sensor for Toxic Materials Accusation

Abstract

The THz plasmonic metasurface (TPM) sensor has emerged as a benchmark principle for harnessing and manipulating light at the nanoscale and enabling to use in optical functionalities for the detection of different analytes in liquid and solid phases. Plasmonic sensors with very high sensitivity and precision are particularly important to the fields of chemical and biological materials like ammonia and urea quality monitoring. In this article, we present a four-band plasmonic metasurface (PMS) structure with very high sensitivity (SS), figure of merit (FoM), and magnetic-field intensity enhancement (MFIE). Max MFIE in four bands of the proposed PMS sensor has been generated by strong coupling between input waves and surface plasmon polaritons (SPPs) that show very narrow bands and harness the light in near-infrared regime. The narrow absorption spectra lead the gigantic MFIE in four bands that generated due to the excitation of the SPPs in the edge of the metal thin film and support the transverse magnetic (TM) surface mode. The optical responses of the presented PMS sensor have be shown the best characteristics/operation max sensitivity, FoM, and MFIE that obtained as 1300 nm per refractive index unit (nm/RIU), 79, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.3\times 10^{{8}}$ </tex-math></inline-formula> , respectively. Results show that the sensor has several high and outstanding performances in comparison with other sensors in the last decade. Also, the presented sensor is valuable and satisfactory in the case of a tunable and compact footprint device. Accordingly, the findings have revealed that the interested four-band PMS is a practical work in different sensor applications such as biochemical and refractive index sensing.

Topics & Concepts