A three-level atom interacting with a strong and a weak monochromatic laser is investigated by means of the dress unitary transformation technique. The two-photon process characteritics is analysed and the fluorescence spectrum of atom is presented, it is shown that they depend on both the intensity of driving field and the detuning.
The influence of the standing wave amplitude on the resonance fluorescence of a three-level system of radiators is discussed. Great attention is devoted to the peculiarities of dressed states in the standing wave and the exchange integrals between two atoms situated in the anti-nodes or the nodes. The correlation functions of emitted photons at two dressed frequencies were obtained. It is shown that in the case when the distance between two atoms is smaller than the wavelength of the field, the emitted photons are strongly correlated. As was observed, for large values of laser field intensity, the control of spontaneous emission is possible at two frequencies as well as the atom–atom interaction process. The dependence of the fluorescent light spectrum as a function of the position of two atoms dressed in the standing wave is investigated.
This investigation describes the interaction of a three level atom with two laser fields. One of the transitions from the ground state is in resonance with twice the frequency of the first laser and the other transition from the ground state is in resonance with the second laser. The Green's function formalism is used to derive expressions from which the induced two photon and one photon excitation spectra are computed. Also, approximate expressions are derived for the excitation spectra in the appropriate frequency regions. These results agree well with the numerical computations based upon the precise expressions. The interference between the two transitions produce some splittings; these splittings depend upon the Rabi frequency of the one photon transition. The intensities of the weak peaks depend upon the ratio of the Rabi frequency of the two photon transition to the frequency of the first laser. Some features of the excitation spectra are interpreted in terms of previous knowledge about the behavior of two level atoms in strong laser fields.
Resonance-fluorescence power spectrum of two-level atoms driven by a strong monochromatic laser field is discussed, taking into account effects due to the dipole-dipole interaction between the atoms. For two atoms confined to a region smaller than the wavelength of the driving field, we predict significant deviations of the power spectrum from the single-atom case. The two-atom spectrum is nonsymmetric, the wing peaks are shifted from their Rabi-frequency positions, and additional maxima may appear.