The Phase-dependent Resonance Fluorescence Of A Three-level Atom

The study of spectral properties of the radiation field scattered by an atom is fundamental to a number of research disciplines in optics and laser physics and provides a convenient ground for rigorous examination of the characteristics of atoms and their interaction with the radiation field. In this paper, the control of the atomic spontaneous emission is discussed by using the relative phase difference of the polychromatic field and certain results are obtained.In this thesis, the resonance fluorescence spectra of a A-type three-level atom is calculated, which is driven by two bichromatic fields having the same difference of the frequency. In addition, the influence of the relative phase difference on the fluorescence spectra are considered. It is found that the fluorescence spectra of the atom are deeply depend on the relative difference and the appearance and cancellation of the fluorescence are obtained by changing the relative phase difference. The spectra keep its characters unchanged, when the relative phase difference is a constant no matter how the respective phase varies; while the relative phase difference is zero and the Rabi frequency is proportional to each other, because of the population trapping, the spectra disappear; when it equals π/2, there is the fluorescence and two-peak structure appear in the central region; when it is changed to π, the spectra are partially restrained. In fact, the phase dependence of fluorescence spectra is attributed to the fact that four different field components induce the transitions in a closed loop configuration.