Design and characterization of a low-loss, dispersion-flattened photonic crystal fiber for terahertz wave propagation

A porous core photonic crystal fiber, based on Topas, with ultra-low effective material loss and near zero flattened dispersion properties is proposed for efficient polarization preserving transmission of terahertz waves. The Finite Element Method (FEM) with a Perfectly Matched Layer (PML) boundary condition is used to compute the modal characteristics of the fiber that confirms a lower Effective Material Loss (EML) of 0.034 cm−1, lower confinement loss of the order of 10−3.7 cm−1, higher effective mode area of 0.6 × 106 μm2 and a flattened dispersion variation of 0.09 ps/THz/cm. In addition, some other characteristics including birefringence, single mode operation, core power fraction and Figure of Merit (FOM) of the proposed fiber are also discussed. To simplify the fabrication process, only circular shaped air holes with a conventional hexagonal structure in the cladding is deployed. It is anticipated that, this newly proposed waveguide will open a new window for further terahertz research and broadband transmission of terahertz radiation.