Low-loss and dispersion flattened terahertz fiber

A porous core photonic crystal fiber (PCF) for terahertz (THz) wave propagation is reported in this paper. The core structure is positioned at ninety degrees to the cladding lattice which allows us to extend the porosity of the fiber to 70 %. Numerical results obtained from an efficient finite element method (FEM) show that the fiber has a very low effective absorption loss (0.06 cm⁻¹) at the operating frequency f = 1 THz and a flattened dispersion of ±0.06 ps/THz/cm within a wide frequency band of 0.45–1.25 THz. The fiber can be manufactured using drilling and drawing methods. It is anticipated that the proposed structure would be useful in a wide range of THz appliances.