title: Experimental demonstration of fractional orbital angular momentum entanglement of two photons.
abstract: The singular nature of a noninteger spiral phase plate allows easy manipulation of spatial degrees of freedom of photon states. Using two such devices, we have observed very high-dimensional spatial entanglement of twin photons generated by spontaneous parametric down-conversion.
authors.affiliation: Huygens Laboratory, Leiden University, Post Office Box 9504, 2300 RA Leiden, The Netherlands.
authors.forename: S S R
authors.initials: SS
authors.lastname: Oemrawsingh
authors.forename: X
authors.initials: X
authors.lastname: Ma
authors.forename: D
authors.initials: D
authors.lastname: Voigt
authors.forename: A
authors.initials: A
authors.lastname: Aiello
authors.forename: E R
authors.initials: ER
authors.lastname: Eliel
authors.forename: G W
authors.initials: GW
authors.lastname: 't Hooft
authors.forename: J P
authors.initials: JP
authors.lastname: Woerdman