title: Nonlinear conversion of photon spin to photon orbital angular momentum.
abstract: A relativistically intense, ultrashort laser pulse with purely spin angular momentum produces second-harmonic radiation with equal parts of both spin and orbital angular momentum when focused into a plasma. The orbital contribution is due to an azimuthal phase variation that arises in the nonlinear current density. This phase variation is associated with the radial nonuniformity driven by ponderomotive blowout.
authors.affiliation: Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375, USA. daniel.gordon@nrl.navy.mil
authors.forename: D F
authors.initials: DF
authors.lastname: Gordon
authors.forename: B
authors.initials: B
authors.lastname: Hafizi
authors.forename: A
authors.initials: A
authors.lastname: Ting