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Title: Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification

Abstract

Short laser pulse amplification via stimulated Brillouin backscattering in plasma is considered. Previous work distinguishes between the weakly and strongly coupled regime and treats them separately. It is shown here that such a separation is not generally applicable because strong and weak coupling interaction regimes are entwined with each other. An initially weakly coupled amplification scenario may dynamically transform into strong coupling. This happens when the local seed amplitude grows and thus triggers the strongly driven plasma response. On the other hand, when in a strong coupling scenario, the pump pulse gets depleted, and its amplitude might drop below the strong coupling threshold. This may cause significant changes in the final seed pulse shape. Furthermore, experimentally used pump pulses are typically Gaussian-shaped. The intensity threshold for strong coupling may only be exceeded around the maximum and not in the wings of the pulse. Also here, a description valid in both strong and weak coupling regimes is required. We propose such a unified treatment which allows us, in particular, to study the dynamic transition between weak and strong coupling. Consequences for the pulse forms of the amplified seed are discussed.

Authors:
; ; ;  [1]
  1. Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf (Germany)
Publication Date:
OSTI Identifier:
22599985
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLIFICATION; AMPLITUDES; BACKSCATTERING; GAUSSIAN PROCESSES; INTERACTIONS; LASERS; PLASMA; PULSE SHAPERS; PULSES; STRONG-COUPLING MODEL

Citation Formats

Schluck, F., Lehmann, G., Müller, C., and Spatschek, K. H.. Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification. United States: N. p., 2016. Web. doi:10.1063/1.4960028.
Schluck, F., Lehmann, G., Müller, C., & Spatschek, K. H.. Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification. United States. doi:10.1063/1.4960028.
Schluck, F., Lehmann, G., Müller, C., and Spatschek, K. H.. 2016. "Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification". United States. doi:10.1063/1.4960028.
@article{osti_22599985,
title = {Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification},
author = {Schluck, F. and Lehmann, G. and Müller, C. and Spatschek, K. H.},
abstractNote = {Short laser pulse amplification via stimulated Brillouin backscattering in plasma is considered. Previous work distinguishes between the weakly and strongly coupled regime and treats them separately. It is shown here that such a separation is not generally applicable because strong and weak coupling interaction regimes are entwined with each other. An initially weakly coupled amplification scenario may dynamically transform into strong coupling. This happens when the local seed amplitude grows and thus triggers the strongly driven plasma response. On the other hand, when in a strong coupling scenario, the pump pulse gets depleted, and its amplitude might drop below the strong coupling threshold. This may cause significant changes in the final seed pulse shape. Furthermore, experimentally used pump pulses are typically Gaussian-shaped. The intensity threshold for strong coupling may only be exceeded around the maximum and not in the wings of the pulse. Also here, a description valid in both strong and weak coupling regimes is required. We propose such a unified treatment which allows us, in particular, to study the dynamic transition between weak and strong coupling. Consequences for the pulse forms of the amplified seed are discussed.},
doi = {10.1063/1.4960028},
journal = {Physics of Plasmas},
number = 8,
volume = 23,
place = {United States},
year = 2016,
month = 8
}
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