A highly birefringent slotted-core THz fiber

We present a slotted porous-core microstructure polymer fiber for polarization maintaining (PM) guidance of terahertz (THz) waves. The numerical analysis is performed using a full vector finite element method (FEM). Our proposed structure contains a compact hexagonal lattice in the cladding and rectangular slotted air-holes inside the core. Geometries inside the core have been designed to introduce asymmetry which results in a high modal birefringence of ~0.08. Moreover, majority of the mode power is propagated in air medium to exhibit a very low effective material loss of ~0.08 cm^-1. Some other modal characteristics of the fiber are also discussed rigorously, which include confinement loss, mode power fraction, dispersion properties etc.