Ultra-low loss polymer-based photonic crystal fiber supporting 242 OAM modes with high bending tolerance for multimode THz communication

Abstract

A novel polymer-based ring-core circular photonic crystal fiber (C-PCF) is proposed and investigated. The solid core C-PCF structure is composed of Topas as background material, a high refractive index (RI) Kapton polymer as a ring material and four layers of air hole patterns. Numerical simulation is used to optimize the PCF geometry to support maximum stable modes with minimum losses. The proposed C-PCF supports 242 stable OAM modes near 1.9 THz with mode purity >0.9. The fiber exhibit low confinement loss (CL) ∼10-9 dB/cm, large effective mode area ∼ 10-2 mm2, low dispersion 10-3 in the range 1.5 THz to 3.5 THz. Attenuation, mode stability, material dispersion and fiber bending tolerance of PCF are analyzed to increase the transmission capacity. The detailed experimental feasibility and design sensitivity are theoretically addressed. The proposed PCF supports stable modes and works at a wider spectrum then the previously reported studies. The fiber has the potential to be employed for next-generation THz multimode communication systems.

Keywords

• Photonic crystal fiber
• Orbital angular momentum
• THz photonics
• Optics