Design and optimization of a PCF-based chemical sensor in THz regime

Abstract In terahertz frequency (THz), we have proposed a hollow core photonic crystal fiber (HC-PCF) to sense chemical. The proposed sensor consists of square shaped air holes in the cladding region with a dumbbell shaped core which has been used to fill with sample liquid. A wide range of frequency has been considered to analysis the performance of the sensor in term of relative sensitivity, effective material loss, confinement loss and effective mode area. Finite element method (FEM) has used to design and analysis numerically the optical parameters of our proposed HC-PCF sensor. To optimize the fabrication tolerance and sensing performance of the proposed sensor, square shaped air holes length, strut and core size has been also studied. Maximum relative sensitivity of 96.25%, confinement loss of 2.11×10−14 cm−1, effective material loss of 9.16×10−4 cm−1 and effective mode area of 1.29 × 106μm2 has been obtained at optimal conditions for the proposed HC-PCF sensor. We strongly believe that the optimized geometrical structure of the proposed sensor will be fabrication friendly and the sensor will contribute in real life applications.