Quasi-Photonic Crystal Fiber-Based Spectroscopic Chemical Sensor in the Terahertz Spectrum: Design and Analysis

In this paper, a novel microstructure quasi-photonic crystal fiber design is proposed. Aimed at a high relative sensitivity, it is targeted for chemical sensing applications in the terahertz regime. A rigorous full-vector finite element method-based numerical investigation has been applied by employing an anisotropic perfectly matched layer for optimizing key parameters. Improved relative sensitivity responses of 78.8%, 77.8%, and 69.7% are achieved for targeted analytes ethanol, benzene, and water, respectively, at the operating frequency of f =1.3 THz. Moreover, confinement loss, effective area, power fraction, and numerical aperture are analyzed from 0.8 to 2.0 THz.