Design and optimization of terahertz directional coupler based on hybrid-cladding hollow waveguide with low confinement loss*
Yu Ying-Ying†, Li Xu-You, Sun Bo, He Kun-Peng
       
Variations of confinement loss of low-confinement-loss frequency regimes with frequency for dielectric layer thickness (a) t 1 = 0.2 mm, (b) t 1 = 0.22 mm, (c) t 1 = 0.24 mm when metallic layer thickness t 2 = 0.30 mm, 0.35 mm, and 0.40 mm.