Investigation of Optical Smoothing Techniques on Multiple Beams

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 combined laser electric fields of overlapping NIF 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.

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