Stimulated Raman backscatter in the kinetic regime of lasers with orbital angular momentum
ORAL
Abstract
In the field of the nonlinear optics of plasmas, stimulated Raman scattering (SRS) has been actively studied because this process is deleterious to inertial confinement fusion. While SRS has been studied extensively for plane waves and single and multiple speckled beams, there has been little work on SRS of a laser with orbital angular momentum (OAM.) SRS of a laser with OAM introduces an additional matching condition for the angular momentum index, l, in addition to the frequency and wavenumber matching conditions. Therefore, a given laser can scatter into a number of different modes with different angular momentum and create plasma waves with OAM. The OAM of the plasma wave can affect its nonlinear damping rate and therefore the growth of backscattered SRS-driven light waves. Lasers and plasma waves with OAM can only be studied in 3D geometry. We present preliminary results of SRS of lasers with OAM using the Quasi-3D OSIRIS particle-in-cell code and the fluid code pF3D. Simulations results of driven plasma waves with OAM will also be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, by DE-NA0003842, and by DE-SC0019010.
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Presenters
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Sarah E Chase
- University of California, Los Angeles