Hybrid porous-core microstructure terahertz fibre with ultra-low bending loss and low effective material loss

A hybrid porous-core microstructure optical fibre (MOF) is proposed and its guiding properties are characterised for efficient terahertz wave guiding. A numerical investigation using the finite element method showed that a hybrid-core MOF consisted of a diamond-shaped cell and the circular arrangement of air holes exhibited an extremely low-bending loss of 5.24 × 10^-13 cm^-1 for a bending radius of 1 cm and an operating frequency of 1.0 THz. The proposed fibre also showed a low effective material loss of 0.08 cm^-1 at an optimised core porosity of 52%. Moreover, single mode propagation, dispersion and fabrication feasibility of the proposed MOF are discussed. Due to the excellent guiding properties, this MOF can be potentially used in THz imaging, sensing and flexible communication applications.