Porous core photonic crystal fibre with metal-coated central hole for terahertz applications

In this study, a novel design of porous octagonal photonic crystal fibre with a metal-coated central hole is investigated and analysed in the terahertz (THz) range. The suggested structure is analysed near a frequency of 1.0 THz by using the full vectorial finite difference method. The effects of the structure geometrical parameters and bending radius on the mode effective index, effective mode area and attenuation of the proposed design are investigated. The numerical results reveal that the effective mode area with a metal-coated central hole is smaller than that of porous core without a metal-coated central hole by 80%. In addition, very low attenuation can be obtained because of the porosity inside the core region.