Plasma prism compressor for high power lasers

Current pulse compressors in high energy ultrafast lasers rely on large diffraction gratings to compress the chirped, amplified pulse to bandwidth limit. Using plasma elements has been proposed as an alternative medium which could withstand a higher intensity than physical material. Purpose of this study is to show feasibility of a prism pulse compressor using plasma elements. The spectral phase up to third order incurred on a linearly chirped Gaussian pulse travelling through the plasma compressor is analytically derived and implemented in a Python raytracing model. The third order phase incurred by the prisms is corrected for using a rectangular slab of plasma with a polynomial density profile. Model results are verified using particle-in-cell simulations in OSIRIS. Given a stretched pulse, the raytracing code is used to find the optimal prism arrangement to compress the pulse. This prism geometry is then simulated in OSIRIS. The compression is quantified by comparing the post-system FWHM to the bandwidth-limited minimum pulse length. Two full-length OSIRIS simulations were run. One compressed a 166 fs pulse to 22 fs FWHM, a compression ratio of 7.5 and 1.3 times the bandwidth limit. The second compressed a 1666 fs pulse to 45 fs, a compression ratio of 37 and 2.8 times the bandwidth limit. Intensity limits like self-focusing and stimulated Raman scattering were not observed in the OSIRIS simulations. Plasma prism compression are a feasible alternative for diffraction gratings for chirped pulse compression.