Resonance lineshapes in multi-level atomic systems

M. Allegrini, E. Arimondo

The lineshapes originated in a magnetic resonance process for atomic alignment are compared to the lineshapes associated to the resonance of coherent population trapping in a three-level system. An approach based on the tensorial components of the atomic density matrix is applied to analyze both resonances and to evidence the strict relations between the lineshapes.

P. A. Hackett, R. A. Back

U. Fano

J.A. Hermann, S. Swain

Exact expressions for the transition probabilities of a three-level atom interacting with a rotating magnetic field are obtained, and used to obtain the double-quantum resonance shift of sixth order and the linewidths to fourth order of perturbation theory. The treatment is extended to deal with overlap effects, oscillating fields and atomic systems with more energy levels. Numerical calculations are performed to check the validity of the analytic expressions and to obtain results applicable at higher field strengths. Although the majority of the detailed work is concerned with the double-quantum resonance, the formalism is general, and the methods may be applied to single-quantum or higher multiple-quantum transitions.

甘雪涛 Gan Xuetao, 赵建林 Zhao Jianlin

Carsten Szymanowski, Christoph H. Keitel, Bryan J. Dalton +1 more

We investigate the structure of the dispersion and absorption lineshapes for driven two-level systems against a weak probing laser field. It is shown that the shape of both curves depends critically on the detuning of the driving laser to the atomic resonance frequency and can be transformed continuously and oppositely between Rayleigh (or ‘dispersion-like’) and Lorentzian (or ‘absorption-like’) lineshapes. An analysis in the dressed state basis explains these features via the different influences of coherences and populations of the corresponding dressed states.