title: Near-perfect sorting of orbital angular momentum and angular position states of light.
abstract: We present a novel method for efficient sorting of photons prepared in states of orbital angular momentum (OAM) and angular position (ANG). A log-polar optical transform is used in combination with a holographic beam-splitting method to achieve better mode discrimination and reduced cross-talk than reported previously. Simulating this method for 7 modes, we have calculated an improved mutual information of 2.43 bits/photon and 2.29 bits/photon for OAM and ANG modes respectively. In addition, we present preliminary results from an experimental implementation of this technique. This method is expected to have important applications for high-dimensional quantum key distribution systems.
authors.affiliation: The Institute of Optics, University of Rochester. 320 Wilmot BLDG, 275 Hutchison Rd, Rochester, NY 14627, USA.
authors.forename: Malcolm N
authors.initials: MN
authors.lastname: O'Sullivan
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mirhosseini
authors.forename: Mehul
authors.initials: M
authors.lastname: Malik
authors.forename: Robert W
authors.initials: RW
authors.lastname: Boyd