Development and Analysis of a Zeonex-Based PCF Chemical Sensor Working in the Terahertz Regime

Photonic crystal fibre (PCF) has gained significant attention in recent years for its potential in terahertz spectrum sensing. By adjusting the structural parameter, one can control the optical characteristics of photonic crystal fibre. A hollow-core photonic crystal fibre was utilised to develop a low-loss terahertz sensor for chemical detection inside the terahertz frequency range in this research. The design we propose features air vents in the outer layer arranged in a hexagonal pattern, while the inner core consists of isosceles triangles and rectangles. An optical study of the design was undertaken using the full vectorial finite element technique (FEM) in combination with COMSOL multiphysics. The quantitative results of our proposed design have undergone substantial improvement. The simulation findings indicate that in the x-polarisation mode, the relative sensitivity for ethanol and benzene is 90.03% and 89.63%, respectively, at the optimal condition. Additionally, the simulation shows a low confinement loss of 2.12x 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–13</sup> cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> and a low eml of 0.026 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> This research also presents information on the physical characteristics and quantitative efficiency evaluation.