Highly Effective PCF Sensor for Ensuring Edible Oil Safety and Quality Within the THz Regime

ABSTRACT This research presents a novel square hollow‐core photonic crystal fibre (PCF) sensor designed for the detection of food‐grade oils in the terahertz (THz) frequency range. The sensor’s effectiveness is quantitatively evaluated using COMSOL Multiphysics, a sophisticated simulation tool that employs finite element methodology (FEM) to model complex interactions within the fibre structure. Simulation outcomes reveal that, under optimal geometric parameters, the proposed sensor achieves an exceptional relative sensitivity of 98.27% for various edible oils at an ideal frequency of 2.2 THz, significantly outperforming existing technologies. Additionally, the sensor exhibits minimal confinement loss of 1.428 × 10 −8 dB/m and a low effective material loss of 0.004246 cm −1 , facilitating accurate detection of slight refractive index variations related to the chemical compositions of different oils. This high sensitivity enables non‐destructive testing, allowing for the analysis of oils without compromising their composition or quality, thereby maintaining the integrity of food products. Ultimately, the proposed PCF sensor enhances food safety monitoring and paves the way for advanced applications in the food industry, ensuring consumers receive high‐quality products.