Ultrasensitive Photonic Crystal Fiber Sensor for Identifying Various Explosives.

The present work has been performed with an intent of designing a robust, profound, and highly sensitive sensor for numerous explosive detections. The main objective of the present study is to design a simplified structure with fabrication feasibilities. The proposed structure of an explosive detector includes a hollow core surrounded with four sectored-type air holes in the cladding area and silica as background of the fiber which operates for 1–2 THz frequency band. Furthermore, the optical guiding property of the detector is examined, and numerical study has been performed. The modelling has been performed with the help of COMSOL Multiphysics 5.6a software based on finite element method, and Origin 2023 software is used for plotting and analyzing the characteristic curves. The suggested sensor structure has been analyzed for various explosives such as TNT, RDX, HMX, and PETN. Optical parameters such as effective refractive index, confinement loss, effective area, nonlinearity, propagation constant, and relative sensitivity have been evaluated. The proposed structure offers relative sensitivity of 84.02%, 69.42%, 71%, and 79.31% for TNT, RDX, HMX, and PETN samples, respectively. The proposed detector structure offers better sensing proficiency for explosive detection. The simplified design favors the fabrication possibilities and makes it economically effective. The proposed study will add up to the developments in the field of photonics and chemical detection and, moreover, will open new doors for better application for security and explosive sensing. [ABSTRACT FROM AUTHOR]