Parametric decay of electromagnetic waves into two plasmons and its consequences

Abstract

The parametric decay of the laser radiation into two plasma waves at the quarter critical density of an inhomogeneous plasma is analyzed. The growth rate and threshold of the absolute instability are derived. The bound on the saturation level of the plasma waves is obtained from the consideration of the pump depletion. The scattered radiation at 3/2 ω0 due to the beating of the incident wave with the backward plasma wave is calculated and compared with observations.