title: Tripartite nonseparability in classical optics.
abstract: It is possible to prepare classical optical beams which cannot be characterized by a tensor product of vectors describing each of their degrees of freedom. Here we report the experimental creation of such a nonseparable, tripartite GHZ-like state of path, polarization, and transverse modes of a classical laser beam. We use a Mach-Zehnder interferometer with an additional mirror and other optical elements to perform measurements that violate Mermin's inequality. This demonstration of a classical optical analogue of tripartite entanglement paves the path to novel optical applications inspired by multipartite quantum information protocols.
authors.forename: W F
authors.initials: WF
authors.lastname: Balthazar
authors.forename: C E R
authors.initials: CE
authors.lastname: Souza
authors.forename: D P
authors.initials: DP
authors.lastname: Caetano
authors.forename: E F
authors.initials: EF
authors.lastname: Galvão
authors.forename: J A O
authors.initials: JA
authors.lastname: Huguenin
authors.forename: A Z
authors.initials: AZ
authors.lastname: Khoury