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Proceedings Paper

Tight focusing of radially polarized laser pulses (Conference Presentation)
Author(s): Tae Moon Jeong; Sergei Bulanov; Stefan Weber; Georg Korn

Paper Abstract

The radially- or azimuthally-polarized beam is an example of vector beams on a higher-order Poincare sphere. Recently, much attention has been paid to the vector beams and their basic focusing properties have been studied elsewhere [1]. Among the vector beams, because of the formation of a strong longitudinal electric field with a tight focusing geometry, the radially-polarized beam has been used for direct electron acceleration through the laser-matter interaction. Thus, it is interesting to investigate how strong longitudinal electric field can be formed by the femtosecond high-power laser pulse. In this paper, the field strength of a longitudinal field of a tightly-focused, radially-polarized femtosecond PW laser pulse has been investigated through numerical calculations based on vector diffraction theory [2]. Because a femtosecond laser pulse has a broad spectrum, the field strength for a given wavelength in the laser spectrum should be known for the accurate assessment of field strength of a tightly-focused femtosecond laser spot. In the research, the electric field strengths for all incident wavelength components are directly calculated from a laser spectrum and pulse energy, and used to assess the strength of a tightly-focused electromagnetic field in the focal region. The orbital angular momentum can be imposed to the light by introducing a spiral phase. A vector OAM beam is formed when the orbital angular momentum is imposed to a radially-polarized beam. Thus, the focusing property of the vector OAM beam is also discussed in the paper. The result will provide precise information on electric and magnetic fields which will be helpful in understanding electron motions under strong and unconventional electromagnetic field.

Paper Details

Date Published: 14 May 2019
Proc. SPIE 11039, Research Using Extreme Light: Entering New Frontiers with Petawatt-Class Lasers IV, 110390S (14 May 2019); doi: 10.1117/12.2524654
Show Author Affiliations
Tae Moon Jeong, ELI Beamlines (Czech Republic)
Sergei Bulanov, ELI Beamlines (Czech Republic)
Stefan Weber, ELI Beamlines (Czech Republic)
Georg Korn, ELI Beamlines (Czech Republic)

Published in SPIE Proceedings Vol. 11039:
Research Using Extreme Light: Entering New Frontiers with Petawatt-Class Lasers IV
Georg Korn; Luis O. Silva, Editor(s)

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