Work

Design of weakly coupled few-mode hybrid nested-single tube anti-resonant fiber with low loss

Year: 2025

Type: article

Abstract: In this work, we design a hybrid nested-single tube anti-resonant fiber (HNST-ARF) with few-mode transmission characteristics, aiming at solving the problems of high higherorder mode loss and significant mode crosstalk in conventional hollow-core fibers. After optimization of the structural parameters, the low-loss transmission of LP01, LP11 and LP21 modes can be supported in the range of 1-1.3 μm, with the LP01 confinement loss as low as 4.46×10-7 dB/m, and the confinement losses of the higher-order modes are all lower than 0.001 dB/m. It supports low-loss transmission of LP01 and LP11 modes in the range of 1.3-1.37 μm. The effective refractive index difference between modes is always greater than 1×10-4, which satisfies the weak coupling condition between modes and can effectively suppress inter-mode crosstalk. Further comparative analysis shows that the synergistic effect of gap single-layer tube and symmetric double inner tube design can effectively suppress the cladding leakage and gap mode coupling. In addition, HNSTARF with a bending radius of 10 cm or larger have less impact on the transmission performance of HNST-ARF with fewer modes, and the mode capacity can be dynamically regulated by wavelength selection. This study provides theoretical support and design examples for the application of hollow-core fibers in mode division multiplexing(MDM) systems and high-capacity optical communications.

Source: Optical Fiber Technology

DOI: 10.1016/j.yofte.2025.104495