We report theoretical and experimental studies on generation of high-order optical vortex
beams using fiber-based nanostructured gradient index converters. The components were …

We study the propagation of circularly-polarized optical vortices of higher order topological
charges ℓ≥ 2 in a sandwich of multihelical-anisotropic-multihelical fibers on the basis of the …

We investigate a unidirectional coupled chiral fiber grating (UCFG) with both helical
refractive index (RI) and loss modulation. The two modulations form a π/2 phase difference …

We study the structure of higher order modes in multihelicoidal optical fibers (MHFs) in the
presence of torsional mechanic stress (TMS). We show that at some values of pitch such …

The Su–Schrieffer–Heeger (SSH) system is a popular model for exploring topological
insulators and topological phases in one dimension. Recent interest in exceptional points …

We study propagation of optical vortices (OVs) in coupled parity-time (PT) symmetric
multimode fibers with equal gain and loss. We show that this system has two second-order …

In this paper we have studied influence of attenuation on conversion processes of the
fundamental mode (FM) in multihelicoidal optical fibers (MHF) in the vicinity of the point of …