Tunable high harmonic pulses from nanorings swirled by optical vortices.

  title={Tunable high harmonic pulses from nanorings swirled by optical vortices.},
  author={Jonas W{\"a}tzel and Jamal Berakdar},
  journal={Optics express},
  volume={25 22},
Irradiating intercalated nanorings by optical vortices ignites a charge flow that emits coherent trains of high harmonic bursts with frequencies and time structures that are controllable by the topological charge of the driving vortex beam. Similar to synchrotron radiation, the polarization of emitted harmonics is also selectable by tuning to the appropriate emission angle with respect to the ring plane. The nonequilibrium orbital magnetic moment triggered in a ring tunnels quantum mechanically… 
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