A novel highly sensitive porous core-photonic crystal fiber (PC-PCF) has been designed and analysed for detection of chemical analytes in the terahertz frequency range. The PC-PCF is designed using rectangular structured air holes in the core with a kagome structured cladding. The full vectorial finite element method (FEM) is used to tune the geometrical parameters and to characterize the fiber. Our results demonstrate a high relative chemical sensitivity with significantly lower confinement loss for different analytes. Moreover, the PCF shows near zero dispersion variation, high modal effective area, high birefringence and high numerical aperture (NA). The practical realization of the fiber is feasible with present fabrication techniques. Our optimized PCF has commercial applications in chemical sensing as well as applications in terahertz systems that require guided polarization preserving transmission.

As the research work in surface plasmon resonance (SPR)-based photonic crystal fiber (PCF) is getting tighter, a perfectly circular-shaped PCF with elliptical air holes is proposed where the performance parameters are improved significantly. The performances among our designed elliptical, circular, and rectangular air holes are compared, and the best result is achieved with the elliptical air holes. The technique used for the investigation is the finite element method, and for the simulation of data COMSOL Multiphysics 5.3a software is used. The method covers a wider range of the optical spectrum from 0.59 to 1.05 µm. The highest confinement loss achieved through our design is 340 dB/cm. The wavelength sensitivity and amplitude sensitivity are 13,000 nm/RIU and 1189.46 R I U − 1 , respectively. The sensor resolution is 7.69 × 10 − 6 for our proposed design. The proposed sensor also achieved a maximum birefringence of 2.8 × 10 − 3 , which is, to our knowledge, the highest birefringence reported so far for a PCF-SPR sensor. This enables the fiber to be operated in a dual-polarized mode. The RI for the analyte ranges from 1.33 to 1.40. Based on all the characteristics, the proposed PCF structure can be used effectively for chemical and biomolecular sensing.