Extremely high birefringent terahertz fiber using a suspended elliptic core with slotted airholes

A suspended core microstructured fiber with extremely high birefringence has been proposed for terahertz (THz) wave propagation. An elliptical-shaped core has been formed with slotted rectangular airholes to disrupt the vertical symmetry of the refractive index of the designed fiber. Different design parameters such as the core diameter, ellipticity, porosity, and suspended strut width have been checked to achieve optimum performance from the fiber. The resultant birefringence of the proposed fiber is unprecedented, of the order of 10-1 (1.057×10-1 to be precise) with a low effective material loss of 0.047 cm-1 and confinement loss of 9.4×10-3 cm-1 at 1 THz. The dispersion of the designed fiber is below 1 ps/THz/cm extended over a band of 500 GHz (1-1.5 THz) with almost flat profile. It is expected that this fiber could be useful in interferometry, filtering, and sensing applications in the THz range where polarized lights are favorably essential.