Laser-radiation scattering spectra in three-level quantum systems

É. G. Pestov

A theoretical investigation is reported of the Raman scattering and fluorescence (doublet) spectra of three-level quantum systems subjected to a strong laser field reducing broadening of the spectral lines caused by adiabatic perturbations (elastic collisions). The dependences of the frequency shifts, widths, and integrated intensities of the spectral components of the doublet on the intensity and frequency of the laser field are derived allowing for the influence of this field on the collision dynamics.

Theodor W. Hänsch, HERBERT WALTHER

A. A. Panteleev, V. Roerich, A. N. Starostin

A new method is developed for the description of transfer and scattering of a time-dependent laser pulse, which is based on a hierarchy of Bogoliubov-Born-Green-Kirkwood-Yvone (BBGKY) equations for reduced density matrices. The systems of equations are obtained for the atomic and photon density matrices and the correlation operator in the second-order Born approximation. The system of equations describes stimulated and spontaneous scattering of laser radiation in an optically thin medium, where reabsorption of spontaneous radiation can be neglected. The method proposed in the paper yields for the first time the correct expressions for nonstationary resonance fluorescence spectra, which do not give the negative values for fluorescence intensity. The expressions obtained for the resonance emission spectra coincide in limiting cases with those obtained within the framework of the quantum regression theorem.

K. Talbi, J. El Qars, A. Ainane +3 more

Kumarasiri Konthasinghe, J. Walker, M. Peiris +8 more

We analyze the light scattered by a single InAs quantum dot interacting with a resonant continuous-wave laser. High-resolution spectra reveal clear distinctions between coherent and incoherent scattering, with the laser intensity spanning more than four orders of magnitude. We find that the fraction of coherently scattered photons can approach unity under sufficiently weak or detuned excitation, ruling out pure dephasing as a relevant decoherence mechanism. We show how spectral diffusion shapes spectra, correlation functions, and phase coherence, concealing the ideal radiatively broadened two-level system described by Mollow.

Franz Schwabl, Walter E Thirring