Interaction of relativistically intense axisymmetrically polarized (radially or azimuthally polarized) laser pulses (RIAPLP) with underdense plasma is shown experimentally and theoretically to be essentially different from the interaction of conventional Gaussian pulses. The difference is clearly observed in distinct spectra of the side-scattered laser light for the RIAPLP and Gaussian pulses, as well as in the appearance of a spatially localized strong side emission of second harmonic of the laser pulse in the case of RIAPLP. According to our analysis based on three-dimensional particle-in-cell simulations, this is a result of instability in the propagation of RIAPLP in uniform underdense plasma.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevE.94.063205 | DOI Listing |
Phys Rev E
May 2024
University of Wisconsin, Madison, Wisconsin 53706, USA.
We show in experiments that a long, underdense, relativistic proton bunch propagating in plasma undergoes the oblique instability, which we observe as filamentation. We determine a threshold value for the ratio between the bunch transverse size and plasma skin depth for the instability to occur. At the threshold, the outcome of the experiment alternates between filamentation and self-modulation instability (evidenced by longitudinal modulation into microbunches).
View Article and Find Full Text PDFPhys Rev Lett
March 2024
GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal.
Nanoscale
March 2024
Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland.
Studying photoemission from free, unsupported aerosol particles is a powerful method for gaining insight into light-matter interactions at the nanoscale. We used single-shot velocity map imaging to experimentally measure kinetic energy and angular distributions of ions emitted following interaction of sub-micrometer NaCl particles with femtosecond pulses of near infrared (NIR, 800 nm) and ultraviolet (UV, 266 nm) light. We combined this with time-dependent simulations of light propagation through the particles and a rate equation approach to computationally address the origin of the observed ion emission.
View Article and Find Full Text PDFPhys Rev E
November 2023
Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany.
Volume plasma density gratings receive increasing interest since, compared to solid-state optical media, they posses significantly higher damage thresholds. The gratings are produced by counterpropagating laser pulses in underdense plasma. When analyzing their optical properties, usually they are assumed to be homogeneous in space.
View Article and Find Full Text PDFFront Optoelectron
December 2023
The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA.
The concept of Terahertz Field-Induced Second Harmonic (TFISH) Generation is revisited to introduce a single-shot detection scheme based on third order nonlinearities. Focused specifically on the further development of THz plasma-based sources, we begin our research by reimagining the TFISH system to serve as a direct plasma diagnostic. In this work, an optical probe beam is used to mix directly with the strong ponderomotive current associated with laser-induced ionization.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!