A single mode porous-core square lattice photonic crystal fiber for THz wave propagation

Background: Interests on low-loss terahertz (THz) waveguides are increasing due to their remarkable applications in various fields. Since most the materials are highly absorbent to THz waves therefore it is an ongoing challenge to obtain a low-loss waveguide. This paper presents a novel porous-core square lattice photonic crystal fiber (PCF) for efficient transmission of THz waves. Methods: The guiding properties of the proposed fiber are characterized by using finite element method (FEM) with circular perfectly matched layer (PML) boundary conditions. Results: It is demonstrated that the designed PCF shows very low effective material loss (EML) of 0.076 cm(-1) at 1.0 THz that indicates about 62 % reduction of bulk absorption loss of the background material. In addition to this, the proposed fiber exhibits low confinement loss of 8.96 x 10(-3) dB/cm and low flattened dispersion of 0.96 +/- 0.086 ps/THz/cm for the optimal design parameters. Other important propagation characteristics such as single mode propagation, power fraction, and bending loss are also investigated thoroughly. Conclusions: A porous-core PCF is an efficient mechanism for the transmission of THz waves. The proposed low-loss and low-dispersion PCF can find numerous applications in THz regime.