Simulation of Laser Pulse Amplification in a Plasma by a Counterpropagating Wave

Abstract—Raman amplification of a short laser pulse by a counter-propagating pump in a plasma is simulated with a one-dimensional electromagnetic particle-in-cell code. With a large growth rate due to three wave interaction, the pump pulse is almost totally depleted and the seed pulse is amplified significantly by the transferred energy. A moving window is adopted to enhance simulation efficiency for long interaction length. Index Terms—Lasers, optical pulse compression, Raman scattering. SHORT LASER pulses with high energy are necessary forhigh-intensity laserapplicationssuchas inertialconfinement fusion (ICF), laser wakefield acceleration (LWFA), and X-ray lasers. However, the laser intensity obtained by amplifiers using chirp pulse amplification (CPA) is currently limited to terawatts (10 W) per centimeter by practical limits on the size of diffrac-tion gratings. Recently, a new method for obtaining high lase