Particle-in-cell simulations of kinetic effects in plasma-based backward Raman amplification in underdense plasmas

A one dimensional particle-in-cell study of the kinetic effects involved in plasma-based backward Raman amplification is presented for nonrelativistic laser pulses interacting in underdense thermal plasmas. Simulations are performed to study how effects such as particle heating and trapping, frequency modulations, and wave breaking of the plasma wave can change with different plasma conditions. The result of this parametric scan of plasma density and temperature is the identification of optimal plasma conditions for amplification of an ultrashort seed laser pulse by a pump laser of nonrelativistic intensity. The relevance of this study to possible experimental scenarios is discussed.