title: Observation of optical vortex streets in walking second-harmonic generation.
abstract: We report what is believed to be the first experimental observation of spontaneous nucleation of arrays of optical vortices in the process of second-harmonic generation in a crystal with moderate Poynting vector walk-off, pumped with focused beams containing screw phase dislocations. Our experiments were conducted in lithium triborate under conditions of small-efficiency second-harmonic generation pumped by nanosecond pulses at 1064 nm.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Molina-Terriza
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Petrov
authors.forename: Jaume
authors.initials: J
authors.lastname: Recolons
authors.forename: Lluis
authors.initials: L
authors.lastname: Torner