Coherent Raman and hyper-Raman spectroscopy of excited and autoionizing states of atoms and ions in laser-produced and electric-discharge plasma

Summary The experimental results on four-wave Raman and hyper-Raman scattering in a laser-produced and electric-discharge plasma are presented. It has been shown that in spectra of four-wave mixing processes resonances appear due to the Raman and hyper-Raman scattering on atomic and ionic excited states. The temporal behaviour of the scattered-signal intensity has been found to be connected with the population relaxation of atomic and ionic excited states. We have observed for the first time the resonance in the spectrum of coherent hyper-Raman scattering in electric-discharge plasma associated with the electron transition between the excited and autoionizing state of a copper atom. Paper presented at the ?XI European CARS Workshop?, Florence, Italy, 23–25 March, 1992.