Intensity scaling and saturation of stimulated Raman forward scattering

The intensity scaling of stimulated Raman forward scattering has been measured in preformed laser‐produced plasmas. It was found that predictions based on linear convective theory were consistent with the amount of scattered light measured when the laser intensity was less than about 1×1015 W/cm2. No increase in the amount of scattered light was found for higher intensities. The measured saturation level is compared to several nonlinear models: pump depletion, coupling to Langmuir and ion‐acoustic waves, ponderomotive detuning, wave breaking, and particle trapping. It is found that saturation models based on ponderomotive detuning and on coupling to Langmuir and ion‐acoustic waves are consistent with the experiment.