Design of topas based hollow core antiresonant fiber for terahertz waveguide

Abstract

Novel low loss fiber for THz application offers great potential for optical fiber study. A novel topas based antiresonant hollow core fiber is designed and numerically characterized by finite element method (FEM) based mode solver software. Comsol Multiphysics were used to design and full-vector finite element method with perfectly matched layer (PML) boundary condition is used to investigate the wave guiding property including single mode operation, effective material loss, confinement loss, V-parameter and bending loss. We have found confinement loss as low as 0.000127 dB/m (at 1 THz) and effective loss as low as 0.081236 dB/m (at 1 THz). Our antiresonant fiber offers lower propagation loss in the range of 0.9 THz ‒ 1.4 THz for all models. We have found the lowest propagation loss of 0.083991 dB/m at 1 THz. From 0.77THz to 1.4 THz range of spectrum, flat dispersion was observed. For varying bending radius, very low decreasing bending loss with increasing bending radius was shown. V-parameter was below 2.405 which demonstrates single mode fiber transmission in this study. This unique design of HC-ARF offers ultra flat dispersion profile over a wide THz spectrum. A latest cyclo-olefin polymer (COP) based material, trade name Topas, is chosen as the background material for proposed model because of its unique advantages over other materials. Moreover, it has lower specific gravity, chemical resistance at elevated temperature, higher transparency, lower melt flow index etc. Furthermore, the physical properties of Topas are also suitable for high quality fiber drawing. Fabrication feasibility and tube-based design allow more suitable low loss profile for THz communication.