title: Observation of an x-ray vortex.
abstract: Phase singularities are a ubiquitous feature of waves of all forms and represent a fundamental aspect of wave topology. An optical vortex phase singularity occurs when there is a spiral phase ramp about a point phase singularity. We report an experimental observation of an optical vortex in a field consisting of 9-keV x-ray photons. The vortex is created with an x-ray optical structure that imparts a spiral phase distribution to the incident wave field and is observed by use of diffraction about a wire to create a division-of-wave-front interferometer.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Peele
authors.forename: Philip J
authors.initials: PJ
authors.lastname: McMahon
authors.forename: David
authors.initials: D
authors.lastname: Paterson
authors.forename: Chanh Q
authors.initials: CQ
authors.lastname: Tran
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Mancuso
authors.forename: Keith A
authors.initials: KA
authors.lastname: Nugent
authors.forename: Jason P
authors.initials: JP
authors.lastname: Hayes
authors.forename: Erol
authors.initials: E
authors.lastname: Harvey
authors.forename: Barry
authors.initials: B
authors.lastname: Lai
authors.forename: Ian
authors.initials: I
authors.lastname: McNulty