Research on hollow-core Terahertz fiber based on Bragg anti-resonant elements arranged in a hexagonal structure

A hollow-core terahertz fiber composed of Bragg anti-resonant elements in a hexagonal structure is proposed. The function of Bragg elements on the transmission losses and bending losses of the hollow-core terahertz fiber is investigated using finite element method. Numerical simulations demonstrate that the introduction of Bragg elements for the anti-resonant cladding can significantly reduce the confinement losses of the fiber. The absorption loss shows low dependence on the number of anti-resonant layers. The introduction of the Bragg elements is also contributed to the reduction of the bending loss. It is found that the reduction of the diameter of the outer cladding can effectively reduce the mode coupling between the core and cladding modes. Compared with the anti-resonant hollow-core terahertz fiber composed of only a single dielectric layer, the bending losses of the hollow-core terahertz fiber with the Bragg elements can be reduced by more than an order of magnitude.