Superluminal-subluminal orbital angular momentum femtosecond laser focus\n

0551284 - FZÚ 2022 RIV US eng J - Journal Article
Jeong, Tae Moon - Bulanov, Sergey V. - Hadjisolomou, Prokopis - Esirkepov, T.Z.
Superluminal-subluminal orbital angular momentum femtosecond laser focus
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Optics Express. Roč. 29, č. 20 (2021), s. 31665-31679. ISSN 1094-4087
R&D Projects: GA MŠMT EF15_003/0000449
Grant - others:OP VVV - HiFi(XE) CZ.02.1.01/0.0/0.0/15_003/0000449
Research Infrastructure: ELI Beamlines III - 90141
Institutional support: RVO:68378271
Keywords : polarization * generation * velocity * beams
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.833, year: 2021
Method of publishing: Open access

The interplay between the frequency chirping of a broadband laser pulse and the longitudinal chromatic aberration of a focusing optic introduces the superluminal or subluminal behavior to a laser focus. In this paper, we present an analytic expression for an electric field describing a superluminal or subluminal femtosecond laser focus with orbital angular momentum. The analytic expression for a superluminal or subluminal laser focus is obtained through a diffraction integral, in which the focal length is replaced by a time-dependent focal length under the paraxial approximation, and the Fourier transformation. The speed and pulse duration of a laser focus are determined by the total group delay dispersion and a chromaticity parameter defined by the longitudinal chromatic aberration of a dispersive focusing optic. It is shown that it is possible to generate a several femtosecond superluminal orbital angular momentum laser focus in the focal region.
Permanent Link: http://hdl.handle.net/11104/0326728