Design of vortex optical fibers for RoF systems: Part I: overview and alternative solutions

Generation of Vortex Optical Beams Based on Chiral Fiber-Optic Periodic Structures

“…It was previously mentioned that the generated OAM optical signal can be branched off using an LP-mode splitter. The authors of this work have previously proposed an optical fiber that supports the propagation of optical vortexes [ 34 ]. The proposed fiber design is based on microstructured fibers.…”

“…The proposed fiber design is based on microstructured fibers. It is assumed that the induced chirality on the optical fiber with a special design—microstructured core—will allow us to form the desired order vortex (OAM mode), while the chirality on the standard fiber—the core surrounded by one outer continuous shell—can be used as a “translator”, i.e., vortex-maintaining fiber for relatively long distances (note that ChFBG means not twisted fiber with a chiral diffraction structure in it; meanwhile, in [ 34 ] we consider the whole twisted fiber). For this purpose, a modification of the rotor of the exhaust tower was carried out: engine rotation speed before modernization was 3 rpm.…”

“… ( a ) The relative Δ n between core and cladding for the proposed fiber. One can obtain a ring-structured profile of refractive index; ( b ) the proposed micro-structured fiber with ring-shape hexagonal geometry [ 34 ]. …”