Porous core fiber with hybrid cladding for ultra-flattened dispersion and low loss propagation of terahertz waves

This work proposes a design of a porous-core photonic crystal fiber (PC-PCF) made of a cyclic olefin copolymer, Zeonex, with a hybrid cladding for low-loss terahertz (THz) wave transmission. A combination of circular and elliptical air holes is employed, resulting in a very low material absorption loss of 0.045 ${\mathrm{cm}}^{-1}$ at $D_{\mathrm{core}}$ = 450 µm and f = 1 THz. A flat dispersion of 0.73 ± 0.13 ps/THz/cm is obtained for a broad frequency range of 0.5–1.4 THz. Core diameter and frequency response of other key features such as normalized frequency (V-parameter), confinement loss, effective area, nonlinearity and the percentage of the power flow through different sections of the proposed PC-PCF are also analyzed. Comparing to state-of-the-art, our design is superior in terms of loss, dispersion and power fraction. Our proposed design can be manufactured using the established extrusion process and be used for long distance low-loss Terahertz (THz) communication.