Mitigation of absolute stimulated Raman scattering with 527 nm broadband laser

Laser plasma instabilities play a critical role in inertial confinement fusion. Among these instabilities, stimulated Raman scattering (SRS), or the resonant decay of an incident light into a scattered light and an electron plasma wave, inhibits the coupling of laser energy to the target plasma by diverting laser energy into unwanted directions, and hinders the target compressibility by generating supra thermal electrons that prematurely heat the imploding fuel. To date, the most promising mitigation strategy for SRS instability involves the use of multiple overlapped beamlets with random phase plates and polarization smoothing to reduce the spatial coherence, and broad spectral bandwidths to reduce the temporal coherence. Here, we will present the mitigation study of absolute SRS with 527-nm broadband drivers for plasma conditions relevant to a preconceptual target design of an inertial fusion pilot plant at the company Focused Energy.