Highly dispersive coupled ring-core fiber for orbital angular momentum modes

In this work, we propose and design a highly dispersive coupled ring-core fiber (CRF) with two concentric high-index rings using Schott glass for orbital angular momentum (OAM) modes. By properly selecting the fiber geometrical parameters, the OAM130,1 mode supported in the proposed CRF has a large negative chromatic dispersion (CD) of −20 271 ps/(nm km) at 1260.4 nm. We also show that the proposed CRF could be an excellent candidate for various...