High-Sensitivity Pentagonal-Shaped Plasmonic Photonic Crystal Fiber for Sulfuric Acid Concentration Sensing

Sulfuric acid (H 2 SO 4 ) sensing is essential and demands a lot in manufacturing industries and real-life applications. In this study, a pentagonal-shaped photonic crystal fiber (PCF)-based plasmonic sensor is proposed to sense the concentration levels of H 2 SO 4 . This study is tested for 0%, 10%, 20%, 30%, and 40% H 2 SO 4 mixture with water at 0.8 to1.8 μm wavelength range. For performance analysis of the sensor, a finite element method (FEM) based on COMSOL Multiphysics software is used. The sensor structure includes a large circular core and pentagonal-shaped cladding region. Because of the large circular core, the sensor achieved higher relative sensitivity which is 99.6% with negligible confinement loss (around 0 dB/m) and effective material loss (1.8 × 10 −3 dB/cm) at 1.3 μm optimum wavelength condition. Also, the sensor fabrication complexity is less than others because of core and all the air holes of cladding are circular shape. All things considered, the proposed sensor is remarkable to sense the concentration level of H 2 SO 4 and solves real-world problems.