摘要 :
A study of the secondary instability of a finite-amplitude ion acoustic wave (IAW) affecting the saturation of stimulated Brillouin backscattering (SBS) of laser light in a plasma is presented. The secondary instability of the SBS...
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A study of the secondary instability of a finite-amplitude ion acoustic wave (IAW) affecting the saturation of stimulated Brillouin backscattering (SBS) of laser light in a plasma is presented. The secondary instability of the SBS IAW provides a nonlinear dissipation mechanism for the SBS IAW and can reduce the SBS reflectivity. To better understand the physics of the secondary instability and SBS, particle-in-cell kinetic simulations, analysis of dispersion relations, and integration of coupled mode equations have been undertaken and compared. Among the effects examined are the influences on the secondary instability of the frequency of the primary IAW, the second harmonic IAW, and ion trapping in the primary SBS IAW which affects Landau damping and the IAW frequency.
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We demonstrate a significant reduction of stimulated Brillouin scattering by polarization smoothing in large-scale high-temperature hohlraum plasma conditions where filamentation is measured to be negligible. The stimulated Brillo...
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We demonstrate a significant reduction of stimulated Brillouin scattering by polarization smoothing in large-scale high-temperature hohlraum plasma conditions where filamentation is measured to be negligible. The stimulated Brillouin scattering experimental threshold (defined as the intensity at which 5% of the incident light is backscattered) is measured to increase by a factor of 1.7 - 0.2 when polarization smoothing is applied. An analytical model relevant to inertial confinement fusion plasma conditions shows that the measured reduction in backscatter with polarization smoothing results from the random spatial variation in polarization of the laser beam, not from the reduction in beam contrast.
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Numerical solutions of the equations satisfied by time dependent stimulated Brillouin scattering have been obtained. The results indicate that both the magnitude and conjugation fidelity of the Stokes wave fluctuate on a time scal...
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Numerical solutions of the equations satisfied by time dependent stimulated Brillouin scattering have been obtained. The results indicate that both the magnitude and conjugation fidelity of the Stokes wave fluctuate on a time scale of the order of ten phonon lifetimes. (ERA citation 13:035346)
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Opto-electronic devices and techniques using Brillouin scattering to select a sideband in a modulated optical carrier signal for amplification. Two lasers respectively provide a carrier signal beam and a Brillouin pump beam which ...
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Opto-electronic devices and techniques using Brillouin scattering to select a sideband in a modulated optical carrier signal for amplification. Two lasers respectively provide a carrier signal beam and a Brillouin pump beam which are fed into an Brillouin optical medium in opposite directions. The relative frequency separation between the lasers is adjusted to align the frequency of the backscattered Brillouin signal with a desired sideband in the carrier signal to effect a Brillouin gain on the sideband. This effect can be used to implement photonic RF signal mixing and conversion with gain, conversion from phase modulation to amplitude modulation, photonic RF frequency multiplication, optical and RF pulse generation and manipulation, and frequency-locking of lasers.
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A numerical method for modeling stimulated Brillouin scatter (SBS) in a hydrodynamic simulation code is discussed. Preliminary results using the model show that scattering is reduced as shorter wavelengths are used and for spheric...
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A numerical method for modeling stimulated Brillouin scatter (SBS) in a hydrodynamic simulation code is discussed. Preliminary results using the model show that scattering is reduced as shorter wavelengths are used and for spherical symmetry that ion heating by SBS is not significant since the ions cool by expansion. (ERA citation 04:050908)
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Particle simulations are performed to show that the ion waves resulting from Stimulated Brillouin Scatter (SBS) can trigger the collapse of the plasma waves excited by Stimulated Raman Scatter (SRS). We discuss the effect of this ...
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Particle simulations are performed to show that the ion waves resulting from Stimulated Brillouin Scatter (SBS) can trigger the collapse of the plasma waves excited by Stimulated Raman Scatter (SRS). We discuss the effect of this collapse mechanism on the hot-electron spectrum produced by the electrostatic waves. A fluid model for the coupling of the ion fluctuations to the plasma waves is formulated and we discuss the necessary condition on the SBS to induce collapse of the plasma waves produced by SRS. (ERA citation 10:026462)
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Techniques for producing optical pulses based on Brillouin selective sideband amplification by using a common modulation control signal to modulate both a signal beam to produce multiple sideband signals and a single pump beam to ...
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Techniques for producing optical pulses based on Brillouin selective sideband amplification by using a common modulation control signal to modulate both a signal beam to produce multiple sideband signals and a single pump beam to produce multiple pump beams.
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Gain spectroscopy is a well established technique for the study of nonlinear scattering phenomena. Several capabilities of gain spectroscopy make the technique very powerful for frequency domain measurements of scattering processe...
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Gain spectroscopy is a well established technique for the study of nonlinear scattering phenomena. Several capabilities of gain spectroscopy make the technique very powerful for frequency domain measurements of scattering processes. The use of gain spectroscopy is illustrated by the application of the technique to Brillouin measurements in solids. 21 refs., 2 figs.
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