Second Harmonic Generation of Stimulated Raman Scattered Light in UnderdensePlasmas

摘要

Experiments examining nonlinear scattering mechanisms of high intensity (2 x10(exp 18) W/sq cm) laser light in underdense plasmas were performed. Red-shifted second harmonic emission at 45 from the directly backscattered direction was observed from field ionized plasmas having electron densities ranging up to 10(exp 19) cu cm. This result was due to the doubling of stimulated Raman sidescattered light from the large plasma electron density gradients produced by ponderomotive cavitation.