Ultra-high birefringent low loss suspended elliptical core photonic crystal fiber for terahertz applications

Appl Opt. 2020 Oct 20;59(30):9385-9392. doi: 10.1364/AO.402530.


This paper presents a low loss suspended core microstructured fiber with ultra-high birefringence for terahertz wave guidance. The finite element method (FEM) with a perfectly matched layer is applied to investigate different important properties including effective material loss (EML), birefringence, dispersion, confinement loss, and percentage of power flow through the core. The suspended elliptical core in the design creates asymmetry and results in an unprecedented value of birefringence. The simulated results using FEM at 1 THz show an extremely ultra-high birefringence (the highest, to the best of our knowledge) of 0.1116, a nominal EML of 0.04716cm-1, a negligible confinement loss of 2.65×10-7cm-1, a higher power fraction in the core air of 35%, and an effective modal area of 1.24×105µm. The advancement in technology makes the fabrication possible. The proposed fiber could be used satisfactorily in the terahertz regime for various polarization-preserving applications and coherent communication.