title: Classical to quantum optical network link for orbital angular momentum-carrying light.
abstract: Using orbital angular momentum (OAM) conservation in second-order nonlinear interaction processes, we create a classical to quantum optical network link in the OAM degrees of freedom of light via sum frequency generation, followed by spontaneous parametric down-conversion. Coherent OAM-carrying beams at 1550 nm are up-converted to 525.5-nm OAM-carrying beams in the first crystal, and are used to pump a second crystal to generate non-degenerate OAM entangled photon pairs at 795 nm and 1550 nm. By switching the OAM carried by the classical part, OAM correlation in the quantum part is shifted. High-level OAM entanglements in two-dimensional subspaces are verified.
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Ding
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Shuai
authors.initials: S
authors.lastname: Shi
authors.forename: Bao-Sen
authors.initials: BS
authors.lastname: Shi