PIC simulations of ionizing Raman amplification were performed, showing good agreement with previous results based on simplified 3-wave calculations. The peak unfocused output intensity for ionizing amplification was verified to be limited to I∼1017 W/cm2 by forward Raman scattering of the amplifying seed. The effects of blueshifting of the seed in the ionization layer and ionization-induced formation of a Langmuir wave were also observed but found not significantly to affect the seed amplification. In addition, the blueshifting of the pump laser pulse in propagating through the ionization front of the oncoming seed pulse was shown to have only a small effect for the gas densities of interest in amplification. Finally, it was argued that the transverse ionization fron instability should be suppressed in an ionizing Raman amplifier and not disrupt amplification of the seed. The stabilization with amplification was confirmed by two-dimensional simulations.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics