title: A hollow beam from a holey fiber.
abstract: A high-quality spectrally isolated hollow beam is produced through a nonlinear-optical transformation of Ti: sapphire laser pulses in a higher order mode of a photonic-crystal fiber (PCF). Instead of a doughnut shape, typical of hollow beams produced by other methods, the far-field image of the hollow-beam PCF output features perfect sixth-order rotation symmetry, dictated by the symmetry of the PCF structure. The frequency of the PCF-generated hollow beam can be tuned by varying the input beam parameters, making a few-mode PCF a convenient and flexible tool for the guiding and trapping of atoms and creation of all-fiber optical tweezers.
authors.forename: Ming-Lie
authors.initials: ML
authors.lastname: Hu
authors.forename: Ching-Yue
authors.initials: CY
authors.lastname: Wang
authors.forename: You-Jian
authors.initials: YJ
authors.lastname: Song
authors.forename: Yan-Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Lu
authors.initials: L
authors.lastname: Chai
authors.forename: Evgenii E
authors.initials: EE
authors.lastname: Serebryannikov
authors.forename: Aleksei M
authors.initials: AM
authors.lastname: Zheltikov