Implementation of smoothing by spectral dispersion on Beamlet and NIF

The performance of the Beamlet laser with one dimensional smoothing by spectral dispersion (1D SSD) implemented is investigated. Measurements of the near field beam quality, nonlinear breakup, and transmission through spatial filter pinholes show a modest effect only at large SSD divergence. No measurable effect was found at the divergence level planned for indirect drive ignition experiments. The efficiency of conversion to the third harmonic was also measured with SSD present and found to be somewhat larger than expected from an ideal plane wave model