  The success of direct laser-driven inertial confinement fusion (ICF) relies
critically on the efficient coupling of laser light to plasma. At ignition
scale, the absolute stimulated Raman scattering (SRS) instability can severely
inhibit this coupling by redirecting and strongly depleting laser light. This
Letter describes a new dynamic saturation regime of the absolute SRS
instability. The saturation occurs when spatiotemporal fluctuations in the
ion-acoustic density detune the instability resonance. The dynamic saturation
mitigates the strong depletion of laser light and enhances its transmission
through the instability region, explaining the coupling of laser light to ICF
targets at higher plasma densities.
