Optical nutation with population inversion on Raman transition at pulse biharmonic excitation

Summary form only given. Optical nutation at pulse biharmonic excitation of Raman transition accompanied by considerable, up to inverse, population changes was observed. The optical nutation manifested itself in corresponding changes of polarization and upper level population of the thallium 6P/sub 1/2/-6P/sub 3/2/ transition excited by picosecond pulses of a dye and a Nd:YAG lasers and probed by delayed pulses by means of coherent Raman scattering and third harmonic generation schemes. As a result of the AC Stark shift, the nutation picture strongly depended on the sign of frequency detuning from the transition frequency.