A high-power laser beam propagating through a dielectric in the presence of fluctuations is subject to diffraction, dissipation, and optical Kerr nonlinearity. A method of moments was applied to a stochastic, nonlinear enveloped wave equation to analyze the evolution of the long-term spot radius. For propagation in atmospheric turbulence described by a Kolmogorov-von Kármán spectral density, the analysis was benchmarked against field experiments in the low-power limit and compared with simulation results in the high-power regime. Dissipation reduced the effect of self-focusing and led to chromatic aberration.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.42.000298 | DOI Listing |
Rev Sci Instrum
January 2025
Institute for Physical Chemistry, University of Göttingen, 37077 Göttingen, Germany.
Surface science instruments require excellent vacuum to ensure surface cleanliness; they also require control of sample temperature, both to clean the surface of contaminants and to control reaction rates at the surface, for example, for molecular beam epitaxy and studies of heterogeneous catalysis. Standard approaches to sample heating within high vacuum chambers involve passing current through filaments of refractory metals, which then heat the sample by convective, radiative, or electron bombardment induced heat transfer. Such hot filament methods lead to outgassing of molecules from neighboring materials that are inadvertently heated; they also produce electrons and ions that may interfere with other aspects of the surface science experiment.
View Article and Find Full Text PDFJ Expo Sci Environ Epidemiol
January 2025
Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Background: Elemental analysis of teeth allows for exposure assessment during critical windows of development and is increasingly used to link early life exposures and health. The measurement of inorganic elements in teeth is challenging; laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is the most widely used technique.
Objective: Both synchrotron x-ray fluorescence (SXRF) and LA-ICP-MS have the capability to measure elemental distributions in teeth with each having distinct advantages and disadvantages.
Phys Rev Lett
December 2024
Stanford University, Department of Mechanical Engineering, Stanford, California 94305, USA.
The extreme electric fields created in high-intensity laser-plasma interactions could generate energetic ions far more compactly than traditional accelerators. Despite this promise, laser-plasma accelerator experiments have been limited to maximum ion energies of ∼100 MeV/nucleon. The central challenge is the low charge-to-mass ratio of ions, which has precluded one of the most successful approaches used for electrons: laser wakefield acceleration.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany.
Linear colliders rely on high-quality flat beams to achieve the desired event rate while avoiding potentially deleterious beamstrahlung effects. Here, we show that flat beams in plasma accelerators can be subject to quality degradation due to emittance mixing. This effect occurs when the beam particles' betatron oscillations in a nonlinearly coupled wakefield become resonant in the horizontal and vertical planes.
View Article and Find Full Text PDFLasers Med Sci
January 2025
Laboratory of Pathophysiology Experimental, Postgraduate Program in Health Sciences, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, Brazil.
Unlabelled: This study aimed to evaluate gold nanoparticles (GNPs) and photobiomodulation (PBM), associated with antibothropic serum (AS), to treat a muscle lesion induced by Bothrops jararaca venom.
Methods: 108 Swiss male mice were used, divided into nine groups (n = 12) with different combinations of treatments. Animals were inoculated with 250 µg of B.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!