Generation of THz Radiation from Laser Beam Filamentation in a Magnetized Plasma

M. Singh, S. T. Mahmoud, R. P. Sharma

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


The terahertz (THz) frequency radiation production as a result of nonlinear interaction of high intense laser beam with low density ripple in a magnetized plasma has been studied. If the appropriate phase matching conditions are satisfied and the frequency of the ripple is appropriate then this difference frequency can be brought in the THz range. Self focusing (filamentation) of a circularly polarized beam propagating along the direction of static magnetic field in plasma is first investigated within extended-paraxial ray approximation. The beam gets focused when the initial power of the laser beam is greater than its critical power. Resulting localized beam couples with the pre-existing density ripple to produce a nonlinear current driving the THz radiation. By changing the strength of the magnetic field, one can enhance or suppress the THz emission. The expressions for the laser beam width parameter, the electric field vector of the THz wave have been obtained. For typical laser beam and plasma parameters with the incident laser intensity ≈ 1014 W/cm2, laser beam radius (r0) = 50 μm, laser frequency (ω0) = 1.8848 × 1014rad/s, electron plasma (low density rippled) wave frequency (ω0) = 1.2848 × 1014 rad/s, plasma density (n0) = 5.025 × 1017cm-3, normalized ripple density amplitude (μ)=0.1, the produced THz emission can be at the level of Giga watt (GW) in power.

Original languageEnglish
Pages (from-to)243-250
Number of pages8
JournalContributions to Plasma Physics
Issue number4
Publication statusPublished - May 2012


  • Extended paraxial ray approximation
  • Plasma wave
  • Ponderomotive nonlinearity
  • Self-focusing
  • THz radiation

ASJC Scopus subject areas

  • Condensed Matter Physics


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