Saturation Spectra of the Two-Plasmon Decay Instability

A nonlinear, reduced description of the saturated steady-state turbulence resulting from the two-plasmon decay instability is shown to lead to Langmuir wave and 3/2ω₀ radiation spectra which are in semiquantitative agreement with recent experimental observations of Meyer et al. [Phys. Rev. Lett. 71, 2915 (1993)]. Secondary Langmuir wave decay of the primary unstable waves is shown to be an important process for moderate laser intensities while strong turbulence effects are observed for higher intensities.