We investigate experimentally and numerically the propagation characteristics of laser beams formed by imparting an azimuthal phase lphi to a Gaussian beam, where l is an integer. We find that when high-l beams of a finite extent are focused through a lens, the beams achieve peak intensity and are most sharply defined before and after the focal plane. Additionally, in these regions of highest intensity the effect of aberrations on the beam quality is greatly reduced, which we also demonstrate experimentally and numerically. We present a simple geometrical picture that provides excellent estimates of the beam radius and propagation distance to the plane of peak intensity.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/ao.46.007573 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Tracing the Formation of Femtosecond Laser-Induced Periodic Surface Structures (LIPSS) by Implanted Markers.
ACS Appl Mater Interfaces
December 2024
Institute of Materials Science and Engineering, Chemnitz University of Technology, Erfenschlager Straße 73, Chemnitz 09125, Germany.
The generation of laser-induced periodic surface structures (LIPSS) using femtosecond lasers facilitates the engineering of material surfaces with tailored functional properties. Numerous aspects of their complex formation process are still under debate, despite intensive theoretical and experimental research in recent decades. This particularly concerns the challenge of verifying approaches based on electromagnetic effects or hydrodynamic processes by experiment.
View Article and Find Full Text PDFTaking into account phase-polarization interactions is crucial for the formation of spatially structured laser beams. The effects that arise in this context can lead to the modulation of individual field components and the transformation of the overall light field. In this study, we investigate the impact of phase and polarization distributions with radial dependencies in polar coordinates on the longitudinal component of laser beams passing through a transmissive spatial light modulator (SLM) based on twisted nematic liquid crystals.
View Article and Find Full Text PDFCross-facility absolute charge calibration of scintillating screens for laser wakefield accelerated beam diagnostics.
Rev Sci Instrum
December 2024
Department of Physics, National Central University, Taoyuan 320317, Taiwan.
Scintillation screens are widely used to diagnose high-charge density, low-average current electron beams from laser wakefield accelerators (LWFAs). However, the absolute response between emitted photons and electron charge has only been calibrated at a limited number of facilities, and there have been discrepancies between these calibrations. In this report, we comprehensively revised the absolute charge calibration of two high relative brightness scintillating screens of LANEX Regular (Carestream) and PI200 (Mitsubishi) by employing the high-brightness photoinjector at the National Synchrotron Radiation Research Center (NSRRC), which provides electron beams with variable charges (50-350 pC per pulse) and energies (26.
View Article and Find Full Text PDFOrbital angular momentum of single photons: revealing quantum fundamentals.
Philos Trans A Math Phys Eng Sci
December 2024
School of Physics and Astronomy, The University of Glasgow, Glasgow, G12 8QQ, UK.
In 1992, Allen . (Allen L, Beijersbergen MW, Spreeuw RJC, Woerdman JP. 1992 Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes.
View Article and Find Full Text PDFEnhancement of Harmonic Heating by Magnetized Plasma Series Resonance in Capacitive Radio Frequency Discharges.
Phys Rev Lett
December 2024
Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, People's Republic of China.
We present a novel resonance mode in capacitive radio frequency (rf) discharges in the presence of an oblique magnetic field at low pressures. We observe the self-excitation of high-frequency harmonics of the current in magnetized capacitive rf discharges through the magnetized plasma series resonance (MPSR) induced by applying a low-frequency power. Utilizing an equivalent circuit model, we reveal that these harmonics arise from the hybrid combination of the magnetic gyration of electrons and the PSR.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!