Terahertz Single-Polarization Single-Mode Hollow-Core Fiber Based on Index-Matching Coupling

We have proposed and analyzed a novel terahertz (THz) single-polarization single-mode (SPSM) hollow-core fiber based on the index-matching coupling method. However, its coupling principle is different from the solid-core SPSM fiber. The confinement loss of the index-matched polarization state is increased slightly, while that of the other polarization state is enhanced by nearly two orders of magnitude. In particular, the confinement loss of the index-matched polarization state is only 0.004 dB/m at f = 1.675 THz.