Abstract-Eight-Capillary Cladding THz Waveguide With Low Propagation Losses and Dispersion

Maxim M. Nazarov,  Artur V. Shilov,  Kazbek A. Bzheumikhov,  Zaur Ch. Margushev,  Viktor I. Sokolov, Alexander B. Sotsky,  Alexander P. Shkurinov,

https://ieeexplore.ieee.org/document/8281070

We investigated the perspectives of a hollow core fiber with a cladding of eight polypropylene capillaries that provides flexibility, low propagation losses, and a single-mode regime in the terahertz frequency range. Optimization procedure is developed. The 7-dB/m propagation loss for 1.3-mm core size and 20-cm waveguide length is experimentally demonstrated at 2-2.2 THz frequency band. The measured group velocity dispersion do not exceed 1 ps/(THz·cm). The theoretical calculations based on the method of Green's functions confirm the experimental data, demonstrate the influence of capillary radius and wall thickness and predict 1.7-dB/m propagation losses for optimized geometry.