~0/2 EMISSION AND STIMULATED RAMAN SCATTERING FROM PRE-FORMED PLASMAS

Temporally and spectrally resolved omega 0/2 harmonic emission and stimulated Raman scattering has been observed from thin foils irradiated by double pulse of 0.53 mu m laser light. Asymmetric omega 0/2 spectrum from the prepulse can be explained by the spectral model including 2 omega p-plasmon-photon coupling and the effects of plasmon refraction. The Raman signal from the main pulse is broad corresponding to densities up to 0.22 nc for the Raman process. An anomalous red shift approximately 1000 AA from the omega 0/2 frequency observed during the main pulse indicates inverse resonance absorption of the Raman-plasmons, because the red shift is too large to be explained by the 2 omega p-instability.