title: Vortices in femtosecond laser fields.
abstract: We experimentally generate optical vortices in the output beam of a 20-fs Ti:sapphire laser. Screw phase dislocations are imposed on the spectral components of the short pulses by aligning a computer-generated hologram in a dispersionless 4f setup.
authors.affiliation: Department of Quantum Electronics, Sofia University, 5, J. Bourchier Boulevard, BG-1164 Sofia, Bulgaria.
authors.forename: K
authors.initials: K
authors.lastname: Bezuhanov
authors.forename: A
authors.initials: A
authors.lastname: Dreischuh
authors.forename: G G
authors.initials: GG
authors.lastname: Paulus
authors.forename: M G
authors.initials: MG
authors.lastname: Schätzel
authors.forename: H
authors.initials: H
authors.lastname: Walther