A Highly Sensitive Dual-Core Dual-Open Channel Circular Lattice Based Plasmonic Sensor for Wide Range Refractive Index Detection

This paper involves the utilization of computational analysis to evaluate a sensor constructed from a dual-core-dual-open channel circular-lattice photonic crystal fiber (PCF). The sensor's performance is demonstrated through the finite element method (FEM) with a circular perfectly matched layer (PML) boundary condition. Gold is installed as the active plasmonic material, added externally to the fiber to streamline the production process. Instead of placing the analyte within the air holes, it is conveniently incorporated into the outermost polishing layer, offering a more practical fabrication method. The sensor exhibits impressive sensitivity along a peak wavelength sensitivity of 23,000 nm/RIU, indicating its ability to detect subtle changes in refractive index. Additionally, it boasts a remarkable maximum amplitude sensitivity of 2598 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{RIU}^{-1}$</tex>. The sensor's detection range spans from 1.33 to 1.43 RI, and the study delves into the impact of factors like the analyte layer, air-hole diameter, and plasmonic layer thickness on its performance. This enhanced surface plasmon resonance (SPR) sensor exhibits exceptional sensitivity and a broad detection range, positioning it as a highly promising candidate for detecting biochemical and biological analytes.