Ultra-low material loss microstructure fiber for terahertz guidance

In this letter, we numerically demonstrate a hybrid-core microstructure fiber for low-loss terahertz guidance. A finite element method with circular perfectly matched layer boundary conditions is applied to characterize the guiding properties. It is shown that by using a triangular-core inside a square lattice microstructure exhibits an ultra-low effective material loss (EML) of 0.169 dB/cm and a low confinement loss of 0.087 dB/cm at an operating frequency of 0.75 THz. We also discuss how other guiding properties including power fraction, single mode propagation and dispersion vary with the changing of core diameter and operating frequencies. This low-loss microstructure fiber can be effectively used in numerous applications in the THz regime. © 2017 Photonics Society of Poland.