Dispersion flattened, low-loss porous fiber for single-mode terahertz wave guidance

Abstract

A porous-core circular photonic crystal fiber is designed for low-loss terahertz (THz) wave propagation. The circular arrangement of air holes, both in the periodic cladding and the porous core, makes it possible to guide most of the optical power through low-loss air, which is confirmed by the rigorous analysis of modal properties of the fiber while maintaining the single-mode propagation condition. The simulation results, found by using an efficient finite element method, show that a flattened dispersion of ±0.09 ps/THz/cm within 0.9 to 1.3 THz and an ultra-low material loss of 0.053 cm−1 at f=1 THz is obtained for the reported design at optimal parameters. This kind of structure can be fabricated using capillary stacking or a sol–gel technique and is expected to be useful for wideband imaging and telecom applications.