Design and optimization of terahertz directional coupler based on hybrid-cladding hollow waveguide with low confinement loss<xref ref-type="fn" rid="cpb142473fn1">*</xref>

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

Transverse section of the hybrid-cladding THz hollow waveguide directional coupler.