title: Mode counting in high-dimensional orbital angular momentum entanglement.
abstract: We study the high-dimensional orbital angular momentum OAM) entanglement contained in the spatial profiles of two quantum-correlated photons. For this purpose, we use a multi-mode two-photon interferometer with an image rotator in one of the interferometer arms. By measuring the two-photon visibility as a function of the image rotation angle we measure the azimuthal Schmidt number, i.e., we count the number of OAM modes involved in the entanglement; in our setup this number is tunable from 1 to 8.
authors: Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands. mvexter@molphys.leidenuniv.nl
authors: M P
authors: MP
authors: van Exter
authors: P S K
authors: PS
authors: Lee
authors: S
authors: S
authors: Doesburg
authors: J P
authors: JP
authors: Woerdman