Efficient Raman Amplification past Wavebreaking*

.We present experimental results from the Raman amplification experimental platform at the University of Rochester’s Laboratory for Laser Energetics (LLE). This platform explores Raman amplification in a unique parameter space which includes a multi-joule pump and an adjustable-energy seed with seed intensities up to 7 x 10¹⁵ W/cm², which is significantly more intense than prior experiments. Initial experiments have demonstrated single-pass Raman amplification in multiple focal configurations with energy gain factors as high as 30x, energy transferred to the seed exceeding 220 mJ, and record efficiencies as high as 11.7%. The efficiency is observed to scale with seed intensity.  For intense seed pulses, efficient amplification is seen well into the wavebreaking regime, as predicted by particle-in-cell simulations [1].

 

References:

[1] M. R. Edwards et al., Phys. Plasmas 22, 074501 (2015).