Abstract
This work considers twisted wave propagation in inhomogeneous and unmagnetised plasma, and discusses the wave properties in the cutoff region. The qualitative differences between twisted waves described by a single Laguerre–Gauss (LG) mode, and light springs resulting from the superposition of two or more LG modes with different frequency and helicity are studied. The peculiar properties displayed by these waves in the nonuniform plasma are discussed. The pulse envelope of a light-spring shows a contraction at reflection, which resembles that of a compressed mechanical spring. The case of normal incidence is examined, and nonlinear ponderomotive effects are discussed, using theory and simulations.
Highlights
The problem of electromagnetic wave propagation in nonuniform plasmas, near plasma cutoff, when the wave frequency ω is close to the local electron plasma frequency ωp, has been considered in plasma physics for a very long time
We have considered propagation of twisted waves in inhomogeneous and unmagnetised plasma
We examined the qualitative differences between reflection of a simple twisted wave, described by a single Laguerre–Gauss (LG) mode, and reflection of a light spring, described by a superposition of different LG modes
Summary
The problem of electromagnetic wave propagation in nonuniform plasmas, near plasma cutoff, when the wave frequency ω is close to the local electron plasma frequency ωp, has been considered in plasma physics for a very long time. The problem was revisited in the context of laser–plasma interactions and laser-driven fusion research [3,4] In this context, the mechanisms of resonant absorption [5], excitation of quasi-static magnetic fields [6], and radiation pressure effects [7] have been considered. Qualitative differences between the usual twisted waves, characterised by a single LG mode, and light springs, described by a superposition of OAM modes, are explored in the present work. These differences are due to dispersion, and vanish in a non-dispersive medium.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
