Hybrid entanglement photon pair source for fiber-space flexible QKD network

We report on the experimental demonstration of a source of hybrid entanglement pairs between two different degrees of freedom, a 1550 nm time-bin qubit and an 810 nm polarization qubit. The hybrid entanglement source is constructed of a non-degenerate photon pair source and a format transformer from time encoding to polarization encoding. This entanglement photon source will provide a fiber- space flexible QKD system.