Possible Reduction of Laser-Fusion Target Illumination by Enhanced Stimulated Raman Plasmon Scattering

When the input irradiance $I$ exceeds a threshold value, two mechanisms cause the stimulated Raman scattering by a plasma to increase as $\exp \left(g_E{I}^{2}x\right)$. One mechanism is a nonlinear increase in the plasmon amplitude, and the other is a second-order process of converting two laser photons into a Stokes photon and anti-Stokes photon. In laser fusion, the enhanced scattering by the residual fusion-chamber gas may greatly reduce the laser irradiance at the target. This theoretical possibility should be investigated experimentally.