Four-wave Mixing with Orbital Angular Momentum Light in a Ring-core Fiber

We experimentally demonstrate degenerate intra-modal four-wave mixing (FWM) processes among orbital angular momentum modes in a family designed ring-core fiber. The designed fiber provide both large effective refractive index difference and low dispersion between multiple modes in the C-band. The signal wave with different modes generated by intra-modal FWM processes was examined using mode de-multiplexed system.