Passage of a

W/cm
23470-Å mode-locked laser beam through a few torr of Cs vapor results in efficient parametric conversion of pump light into beams of ultrashort pulses at wavelengths located near the ∼ 3600-Å

and ∼ 3900-Å

Cs resonance lines. In addition, ultrashort pulses at roughly ten different infrared wavelengths lying between ∼ 6 and 20μ are produced. The four- and six-wave parametric processes responsible for the conversion are initiated by stimulated electronic Raman emission.