Bend-Insensitive and Low-Loss Porous Core Spiral Terahertz Fiber

A novel (to the best of our knowledge) kind of porous-core spiral photonic crystal fiber (PCF) is proposed in this letter. It illustrates a tradeoff managed between material absorption and bending loss for efficient guidance of terahertz (THz) waves using a circular lattice array of smaller air-holes inside the core of an equiangular spiral structure. With maximum porosity and operating frequency of 1 THz, bending loss of 4.16×10^-16 cm^-1 and effective material loss of 0.1 cm^-1 are reported. In addition, other modal characteristics, such as effective area, confinement loss, and fabrication techniques of the proposed fiber have been discussed. The proposed THz waveguide can be potentially used for efficient and convenient transmission of THz waves.