Design and analysis of a rectangular core refractive index-based PCF sensor for bio-sensing application

A hollow-core photonic crystal fiber based Refractive Index sensor in the terahertz frequency regime for bio-sensing application is proposed in this paper. Refractive index variation is used for the identification of different analytes with refractive indices ranging from n = 1.35 to 1.39. Zeonex is chosen as the fiber material. The proposed photonic crystal fiber (PCF) sensor features a solitary rectangular core enclosed by an arrangement of 16 rectangular air holes within the cladding area with different heights and widths. Simulation and numerical analysis are conducted using Finite Element Method-based based Comsol Multiphysics Software. The proposed PCF sensor exhibits relative sensitivity of 98.8%, an Effective Mode Area of 1.06  \(\times \hspace{0.17em}\) $\times$ 10⁻⁷ m² with a very low confinement loss of 7.751  \(\times \hspace{0.17em}\) $\times$ 10^–14 dB/cm are achieved at a frequency of 1.4 THz for an analyte of refractive index 1.39 in X Polarization direction of electric field. Moreover, birefringence, non-linearity, effective refractive index and power fraction are also analyzed. Further simple PCF structure based on rectangle ensures that fabrication is feasible with current fabrication techniques.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.I have checked the authors name and affiliations and found its correct.Kindly check and confirm whether the corresponding author and corresponding mail ID is correctly identified.I have checked about corresponding authors name and email id. I found it correct.