Optical nutation in a collinear fast-ion-beam–laser experiment

Optical nutation in Ba ii has been studied with a rapid Doppler-shifting technique in a cw collinear fast-ion-beam--laser experiment. Time-resolved nutation curves have been recorded as a function of transition, laser irradiance, laser frequency detuning, and laser polarization. Frequency spectra recorded at different, well-specified, times of interaction between the ions and the laser field reveal several interesting effects. Among them is the pronounced influence of the postacceleration potential on the line profiles. Theoretical curves, calculated in the density-matrix formalism, reproduce all the characteristics of the experimental data. Future possibilities of this technique are discussed, e.g., the prospects of determining transition probabilities through the measurements of optical nutation.