skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Nonlinear evolution of the plasma beat wave: Compressing the laser beat notes via electromagnetic cascading

Abstract

The near-resonant beat wave excitation of an electron plasma wave (EPW) can be employed for generating the trains of few-femtosecond electromagnetic (EM) pulses in rarefied plasmas. The EPW produces a comoving index grating that induces a laser phase modulation at the difference frequency. As a result, the cascade of sidebands red and blue shifted by integer multiples of the beat frequency is generated in the laser spectrum. The bandwidth of the phase-modulated laser is proportional to the product of the plasma length, laser wavelength, and amplitude of the electron density perturbation. When the beat frequency is lower than the electron plasma frequency, the redshifted spectral components are advanced in time with respect to the blueshifted ones near the center of each laser beat note. The group velocity dispersion of plasma compresses so chirped beat notes to a few-laser-cycle duration thus creating a train of sharp EM spikes with the beat periodicity. Depending on the plasma and laser parameters, chirping and compression can be implemented either concurrently in the same, or sequentially in different plasmas. Evolution of the laser beat wave and electron density perturbations is described in time and one spatial dimension in a weakly relativistic approximation. Using the compressionmore » effect, we demonstrate that the relativistic bistability regime of the EPW excitation [G. Shvets, Phys. Rev. Lett. 93, 195004 (2004)] can be achieved with the initially subthreshold beat wave pulse.« less

Authors:
;  [1]
  1. Department of Physics and Institute for Fusion Studies, University of Texas at Austin, One University Station C1500, Austin, Texas 78712 (United States)
Publication Date:
OSTI Identifier:
20779247
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics; Journal Volume: 73; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevE.73.046403; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; COMPRESSION; ELECTROMAGNETIC RADIATION; ELECTRON DENSITY; ELECTRON PLASMA WAVES; EVOLUTION; EXCITATION; LANGMUIR FREQUENCY; LASERS; MODULATION; NONLINEAR PROBLEMS; PERIODICITY; PULSES; RELATIVISTIC PLASMA; RELATIVISTIC RANGE; SPECTRAL SHIFT; WAVELENGTHS

Citation Formats

Kalmykov, Serguei, and Shvets, Gennady. Nonlinear evolution of the plasma beat wave: Compressing the laser beat notes via electromagnetic cascading. United States: N. p., 2006. Web. doi:10.1103/PHYSREVE.73.0.
Kalmykov, Serguei, & Shvets, Gennady. Nonlinear evolution of the plasma beat wave: Compressing the laser beat notes via electromagnetic cascading. United States. doi:10.1103/PHYSREVE.73.0.
Kalmykov, Serguei, and Shvets, Gennady. Sat . "Nonlinear evolution of the plasma beat wave: Compressing the laser beat notes via electromagnetic cascading". United States. doi:10.1103/PHYSREVE.73.0.
@article{osti_20779247,
title = {Nonlinear evolution of the plasma beat wave: Compressing the laser beat notes via electromagnetic cascading},
author = {Kalmykov, Serguei and Shvets, Gennady},
abstractNote = {The near-resonant beat wave excitation of an electron plasma wave (EPW) can be employed for generating the trains of few-femtosecond electromagnetic (EM) pulses in rarefied plasmas. The EPW produces a comoving index grating that induces a laser phase modulation at the difference frequency. As a result, the cascade of sidebands red and blue shifted by integer multiples of the beat frequency is generated in the laser spectrum. The bandwidth of the phase-modulated laser is proportional to the product of the plasma length, laser wavelength, and amplitude of the electron density perturbation. When the beat frequency is lower than the electron plasma frequency, the redshifted spectral components are advanced in time with respect to the blueshifted ones near the center of each laser beat note. The group velocity dispersion of plasma compresses so chirped beat notes to a few-laser-cycle duration thus creating a train of sharp EM spikes with the beat periodicity. Depending on the plasma and laser parameters, chirping and compression can be implemented either concurrently in the same, or sequentially in different plasmas. Evolution of the laser beat wave and electron density perturbations is described in time and one spatial dimension in a weakly relativistic approximation. Using the compression effect, we demonstrate that the relativistic bistability regime of the EPW excitation [G. Shvets, Phys. Rev. Lett. 93, 195004 (2004)] can be achieved with the initially subthreshold beat wave pulse.},
doi = {10.1103/PHYSREVE.73.0},
journal = {Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics},
number = 4,
volume = 73,
place = {United States},
year = {Sat Apr 15 00:00:00 EDT 2006},
month = {Sat Apr 15 00:00:00 EDT 2006}
}