Amplification of Ultrashort Laser Pulses by Brillouin Backscattering in Plasmas


The research showed the feasibility of achieving light amplification up to very high intensities using controlled Brillouin amplification in a plasma. Plasma media, by exciting Raman (electron) or Brillouin (ion) waves, have been used to transfer energy from moderately long, high-energy light pulses to short ones. Using multidimensional kinetic simulations, we defined the optimum window in which a Brillouin scheme can be exploited for amplification and compression of short laser pulses over short distances to very high power. We also show that shaping the plasma allows for increasing the efficiency of the process while minimizing other unwanted plasma processes. Moreover, we showed that, contrary to what was traditionally thought (i.e., using Brillouin in gases for nanosecond pulse compression), this scheme is able to amplify pulses of extremely short duration. The long-term advantage would be to overcome the inherent damage threshold of standard solid-state based optical materials.

Image 1: Diagram shows the combination of compression, amplification and focusation techniques used in high-energy pulses.
Image 2: Two-dimensional kinetic simulation of seed pulse amplification. The energy is transferred from the low-intensity pump to the seed pulse enetring from the right.