Structure of the resonance-scattering and spontaneous-emission spectra of an atom in a strong monochromatic light field

A. V. Lyaptsev, A. N. Zuev

S P Goreslavsky, Nikolai B. Delone, В. П. Крайнов

The interaction of a two-level atom with two monochromatic electromagnetic fields having arbitrary amplitudes and resonance frequencies is considered. It is shown that the time averaged upper-level population can exceed 0.5 and even reach 0.7. Its dependence on the frequency difference reveals resonance satellite peaks, which are concerned with three- and five-photon combination scattering. The widths and the resonance spectrum shifts of these peaks are found. The frequency spectrum of the spontaneous emission of an atom contains fine structure under some conditions. This structure does not exist in the case of one monochromatic field. An asymmetry in the intensity distribution for the Rabi satellites due to a field non-monochromaticity is predicted.

Anna V. Bogatskaya, A. M. Popov

Tong Zhang, Xu Deng, Kai-Kai Zhang +2 more

We propose an efficient scheme to manipulate spontaneous emission spectra using optical vortices carrying orbital angular momentum (OAM) in a coherently driven cold five-level atomic system assisted by a radio frequency (RF) or microwave field. Using experimentally achievable parameters, we find that the spontaneous emission is strongly influenced by quantum destructive interference. And we show that the structured light profile of the probe field can be transferred to the spontaneous emission spectrum via spontaneously generated coherence (SGC). With the aid of SGC, the intensities and detunings of the control and RF fields can be used to tailor the vortex-induced spontaneous emission spectra. When the control and RF fields are configured as vortex beams, it is demonstrated that the spontaneous emission can be coherently controlled through quantum interference by adjusting their topological charges (TCs). Furthermore, we explore intriguing optical properties of the vortex-induced spontaneous emission by varying the TCs of the probe and control fields. This coherently driven atomic system features three closely spaced levels, giving rise to multiple vortex-induced SGC pathways. Our scheme opens avenues for applications in structured light, ranging from optical storage to optical communication.

Ivan S. Nikolaev, Peter Lodahl, Willem L. Vos

We have performed angle-resolved measurements of spontaneous-emission spectra from laser dyes and quantum dots in opal and inverse opal photonic crystals. Pronounced directional dependencies of the emission spectra are observed: angular ranges of strongly reduced emission adjoin with angular ranges of enhanced emission. It appears that emission from embedded light sources is affected both by the periodicity and by the structural imperfections of the crystals: the photons are Bragg diffracted by lattice planes and scattered by unavoidable structural disorder. Using a model comprising diffuse light transport and photonic band structure, we quantitatively explain the directional emission spectra. This work provides detailed understanding of the transport of spontaneously emitted light in real photonic crystals, which is essential in the interpretation of quantum optics in photonic-band-gap crystals and for applications wherein directional emission and total emission power are controlled.

James D. Cresser, J. Häger, Gerd Leuchs +2 more