TITLE

'Bloch wave' modification of stimulated Raman by stimulated Brillouin scattering

AUTHOR(S)
Dodd, E. S.; Vu, H. X.; DuBois, D. F.; Bezzerides, B.
PUB. DATE
March 2013
SOURCE
Physics of Plasmas;Mar2013, Vol. 20 Issue 3, p032707
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Using the reduced-description particle-in-cell (RPIC) method, we study the coupling of backward stimulated Raman scattering (BSRS) and backward stimulated Brillouin scattering (BSBS) in regimes where the reflectivity involves the nonlinear behavior of particles trapped in the daughter plasma waves. The temporal envelope of a Langmuir wave (LW) obeys a Schrödinger equation where the potential is the periodic electron density fluctuation resulting from an ion-acoustic wave (IAW). The BSRS-driven LWs in this case have a Bloch wave structure and a modified dispersion due to the BSBS-driven spatially periodic IAW, which includes frequency band gaps at kLW∼kIAW/2∼k0 (kLW, kIAW, and k0 are the wave number of the LW, IAW, and incident pump electromagnetic wave, respectively). This band structure and the associated Bloch wave harmonic components are distinctly observed in RPIC calculations of the electron density fluctuation spectra and this structure may be observable in Thomson scatter. Bloch wave components grow up in the LW spectrum, and are not the result of isolated BSRS. Self-Thomson scattered light from these Bloch wave components can have forward scattering components. The distortion of the LW dispersion curve implies that the usual relationship connecting the frequency shift of the BSRS-scattered light and the density of origin of this light may become inaccurate. The modified LW frequency results in a time-dependent frequency shift that increases as the IAW grows, detunes the BSRS frequency matching condition, and reduces BSRS growth. A dependence of the BSRS reflectivity on the IAW Landau damping results because this damping determines the levels of IAWs. The time-dependent reflectivity in our simulations is characterized by bursts of sub-picosecond pulses of BSRS alternating with multi-ps pulses of BSBS, and BSRS is observed to decline precipitously as soon as SBS begins to grow from low levels. In strong BSBS regimes, the Bloch wave effects in BSRS are strong and temporal anti-correlation with BSRS is due to pump depletion in addition to frequency detuning. In most cases studied, BSBS suppressed the time-averaged reflectivity of BSRS compared to the levels obtained with fixed ions (and therefore no BSBS). The strong spatial modulation of the Bloch Langmuir waves appears to weaken electron trapping and thereby lowers the inflated reflectivity levels of BSRS.
ACCESSION #
86447095

 

Related Articles

  • Contribution to half-harmonic splitting resulting from Raman backscattering in a rippled plasma. Figueroa, H.; Joshi, C. // Physics of Fluids (00319171);Jul87, Vol. 30 Issue 7, p2294 

    The dispersion relation of electron plasma waves in a rippled plasma is analyzed. The ripple couples the plasma wave to its spatial harmonics thereby introducing ‘‘forbidden’’ frequency bands. It is shown that the stimulated Brillouin scattering (SBS) induced ripple can...

  • Laser parametric instability experiments of a 3ω, 15 kJ, 6-ns laser pulse in gas-filled hohlraums at the Ligne d'Intégration Laser facility. Rousseaux, C.; Huser, G.; Loiseau, P.; Casanova, M.; Alozy, E.; Villette, B.; Wrobel, R.; Henry, O.; Raffestin, D. // Physics of Plasmas;2015, Vol. 22 Issue 2, p1 

    Experimental investigation of stimulated Raman (SRS) and Brillouin (SBS) scattering have been obtained at the Ligne-d'Intégration-Laser facility (LIL, CEA-Cesta, France). The parametric instabilities (LPI) are driven by firing four laser beamlets (one quad) into millimeter size, gas-filled...

  • Effect of the magnetic field on coexisting stimulated Raman and Brillouin backscattering of an extraordinary mode. Vyas, Ashish; Singh, Ram Kishor; Sharma, R. P. // Physics of Plasmas;2016, Vol. 23 Issue 1, p1 

    This paper presents a model to study the interplay between the stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) in the presence of background magnetic field. This formalism is applicable to laser produced plasma as well as to heating mechanism in toroidal system by an...

  • USAGE OF DISTRIBUTED FIBER OPTICAL TEMPERATURE SENSORS DURING BUILDING REDEVELOPMENT. Vasinek, Vladimir; Smira, Pavel; Rasnerova, Vladimira; Nasswettrova, Andrea; Jaros, Jakub; Liner, Andrej; Papes, Martin // Advanced Materials Research;2014, Issue 923, p229 

    This contribution describes the novel unique technology with the usage of fiber optical sensors with temperature resolution up to 0.01oC and spatial resolution 1m. This technology is supplemented with fiber optical strain sensor with pressure resolution 1Pa. Fiber optical sensors are based on...

  • Raman scattering in a nearly resonant density ripple. Barr, Hugh C.; Chen, Francis F. // Physics of Fluids (00319171);Apr87, Vol. 30 Issue 4, p1180 

    Stimulated Raman scattering of light waves by an underdense plasma is affected by the presence of a density ripple caused by a simultaneously occurring stimulated Brillouin instability. The problem is treated kinetically for the particularly interesting case where the ripple has nearly the same...

  • Interplay between ion acoustic waves and electron plasma waves associated with stimulated... Labaune, C.; Baldis, H.A.; Renard, N.; Schifano, E.; Michard, A. // Physics of Plasmas;Feb97, Vol. 4 Issue 2, p423 

    Investigates the interplay between ion acoustic waves (IAW) and electron plasma waves (EPW) associated with stimulated Brillouin and Raman scattering. Growth of two types of waves over a limited region in the front part of the plasma; Observation of the inhibition of the EPW by the IAW.

  • Stimulated Brillouin scattering during electron gyro-harmonic heating at EISCAT. Fu, H. Y.; Scales, W. A.; Bernhardt, P. A.; Briczinski, S. J.; Kosch, M. J.; Senior, A.; Rietveld, M. T.; Yeoman, T. K.; Ruohoniemi, J. M. // Annales Geophysicae (09927689);2015, Vol. 33 Issue 8, p983 

    Observations of secondary radiation, stimulated electromagnetic emission (SEE), produced during ionospheric modification experiments using ground-based, highpower, high-frequency (HF) radio waves are considered. The High Frequency Active Auroral Research Program (HAARP) facility is capable of...

  • Materials Development for Next Generation Optical Fiber. Ballato, John; Dragic, Peter // Materials (1996-1944);Jun2014, Vol. 7 Issue 6, p4411 

    Optical fibers, the enablers of the Internet, are being used in an ever more diverse array of applications. Many of the rapidly growing deployments of fibers are in high-power and, particularly, high power-per-unit-bandwidth systems where well-known optical nonlinearities have historically not...

  • Flat amplitude multiwavelength Brillouin-Raman random fiber laser with a half-open cavity. Wu, Han; Wang, Zinan; Jia, Xinhong; Li, Peiyun; Fan, Mengqiu; Li, Yi; Zhu, Yeyu // Applied Physics B: Lasers & Optics;Sep2013, Vol. 112 Issue 4, p467 

    In this paper, we experimentally demonstrate a novel configuration of multiwavelength Brillouin-Raman random fiber laser (MBRRFL) utilizing a half-open cavity. The laser resonator is formed by fiber loop mirror at the Brillouin pump (BP) side and random distributed Rayleigh backscattering in a...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics