Laser-Beam Smoothing Induced by Stimulated Brillouin Scattering in an Inhomogeneous Plasma

Journal Article · Fri Nov 17 04:00:00 EST 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.97.205001· OSTI ID:20861149

Loiseau, P; Morice, O; Teychenne, D; Casanova, M; Hueller, S; Pesme, D ^[1]

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1. Commissariat a l'Energie Atomique, BP 12, 91680 Bruyeres-Le-Chatel (France)

We present results of two-dimensional simulations of the stimulated Brillouin scattering (SBS) of an optically smoothed laser beam propagating in an expanding plasma. In the weak damping limit, both backscattered and transmitted light waves exhibit an additional spatiotemporal incoherence, which is shown to be induced by SBS taking place in an inhomogeneous plasma. This mechanism is not related to laser-beam self-focusing and is thus complementary to plasma-induced smoothing [A. J. Schmitt and B. B. Afeyan, Phys. Plasmas 5, 503 (1998)]. The incoherence induced by SBS in the entrance part of the plasma could reduce the growth of parametric instabilities developing further inside the plasma and is able to significantly enlarge the spreading angle of the transmitted light. The angular width of the backscattered light is also found to be significantly larger than the aperture angle of the incident beam.

• OSTI ID: 20861149
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 20 Vol. 97; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BRILLOUIN EFFECT
INHOMOGENEOUS PLASMA
LASERS
LIGHT TRANSMISSION
PARAMETRIC INSTABILITIES
SIMULATION
TWO-DIMENSIONAL CALCULATIONS
VISIBLE RADIATION