Comparison of Optical Smoothing Techniques for LPI Mitigation

Intense laser hotspots/speckles are a concern on high power laser facilities due to their role in seeding unwanted instabilities such as SBS (Stimulated Brillouin Scattering). Optical smoothing techniques such as SSD^1,2 (Smoothing by Spectral Dispersion) are used to better homogenize the laser focal spot intensity pattern on the time scale of the instabilities. Here we report on a project that examines the laser electric fields of NIF like beams including the effects of SSD, polarization rotation, and beat waves³. An overview of the simulation technique will be presented with updates on characterizing various optical smoothing techniques for mitigating LPI (Laser Plasma Instabilities).



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