Aboulwafa M. Singer, Ahmed M. Heikal, Hamdi A. El-Mikati, Salah S. A. Obayya, and Mohamed Farhat O. Hameed, “Ultra-Low Loss and Flat Dispersion Circular Porous Core Photonic Crystal Fiber for Terahertz Waveguiding”, ACES Journal, vol. 35, no. 6, pp. 709–717, Jun. 2020.