Engineering of orbital angular momentum supermodes in coupled optical waveguides

摘要

In this work we demonstrate the existence of orbital angular momentum (OAM)bright and dark supermodes in a three-evanescently coupled cylindricalwaveguides system. Bright and dark supermodes are characterized by theircoupling and decoupling from one of the waveguides, respectively. In addition,we demonstrate that complex couplings between modes of different waveguidesappear naturally due to the characteristic spiral phase-front of OAM modes intwo-dimensional configurations where the waveguides are arranged forming atriangle. Finally, by adding dissipation to the waveguide uncoupled to the darksupermode, we are able to filter it out, allowing for the design of OAM modeclonners and inverters.