Engineering Entangled Photons for Transmission in Ring-Core Optical Fibers

The capacity of optical communication channels can be increased by space division multiplexing in structured fibers. Radial core fibers allows for the propagation twisted light–eigenmodes orbital angular momentum, which have attracted considerable attention high-dimensional quantum information. Here we study generation entangled photons that are tailor-made coupling into ring We show photon pairs produced parametric down-conversion close to a factor three pumping non-linear crystal with perfect vortex mode momentum ℓ , rather than gaussian mode. Moreover, two-photon spectrum has nearly constant shape. This provides an interesting scenario state engineering, as superposition modes used conjunction filtering properties fiber produce simple and states.