Open AccessHigh-order orbital angular momentum generation in a helically twisted pig-nose-shaped core microstructured optical fiber
Author(s) -
Mingjie Cui,
Zhifeng Mo,
Nan Zhao,
Changming Xia,
Zhipeng Hou,
Guiyao Zhou
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.417155
Subject(s) - optics , core (optical fiber) , angular momentum , physics , coupling (piping) , optical fiber , rotation (mathematics) , graded index fiber , fiber , ring (chemistry) , fiber optic sensor , materials science , geometry , classical mechanics , mathematics , metallurgy , composite material , organic chemistry , chemistry
We propose a helically twisted pig-nose-shaped core microstructured optical fiber (HPC-MOF) for orbital angular momentum (OAM) mode generation. It comprises seven air-hole rings hexagonally arranged with two air holes and one air-hole ring replaced, forming two cores in a line 3 µm from the fiber center and one ring-shaped core. The fiber is helically twisted along the rotation axis. In this fiber, supermodes in inner dual-core can be coupled to high-order modes in outer ring-core, yielding OAM ring-shaped modes at different certain wavelengths, and various OAM modes at different twist rates were investigated in this paper. We demonstrate the distinct coupling differences of symmetric and antisymmetric supermodes in inner dual-core when the supermode coupled to ring-core mode. A modal matching rule is presented to characterize the coupling differences, which is suitable for describing supermode coupling characteristics in HPC-MOFs. Compared to conventional methods, these properties indicate that the fiber can generate higher-order OAM modes and more easily integrate into all-fiber optical communication systems, with potential in OAM generators, light-controlling devices, and integrated optics applications.