Fluorescence spectrum of a two-level atom driven by a multiple modulated field

Abstract

We investigate the fluorescence spectrum of a two-level atom driven by a multiple amplitude-modulated field. The driving field is modeled as a polychromatic field composed of a strong central ͑resonant͒ component and a large number of symmetrically detuned sideband fields displaced from the central component by integer multiples of a constant detuning. Spectra obtained here differ qualitatively from those observed for a single pair of modulating fields ͓B. Blind, P.R. Fontana, and P. Thomann, J. Phys. B 13, 2717 ͑1980͔͒. In the case of a small number of the modulating fields, a multipeaked spectrum is obtained with the spectral features located at fixed frequencies that are independent of the number of modulating fields and their Rabi frequencies. As the number of the modulating fields increases, the spectrum ultimately evolves to the well-known Mollow triplet with the sidebands shifted from the central component by an effective Rabi frequency whose magnitude depends on the initial relative phases of the components of the driving field. For equal relative phases, the effective Rabi frequency of the driving field can be reduced to zero resulting in the disappearance of fluorescence spectrum, i.e., the atom can stop interacting with the field. When the central component and the modulating fields are 180°out of phase, the spectrum retains its triplet structure with the sidebands located at frequencies equal to the sum of the Rabi frequencies of the component of the driving field. Moreover, we show that the frequency of spontaneous emission can be controlled and switched from one frequency to another when the Rabi frequency or initial phase of the modulating fields are varied.

Sub-half-wavelength localization of a two-level atom via trichromatic phase manipulation

“…It should be noted that the two-photon transitions have the same phase Φ = φ 1 + φ 2 . The fluorescence spectrum is not determined by the respective phases φ 1 and φ 2 but by the phase sum Φ [47,48]. Due to its dependence on the position-dependent Rabi frequency of the driving field, the spontaneously emitted photon carries the information about the position of the atom.…”

“…The interaction of a polychromatic field with the atom yields many effects that are absent for the monochromatic excitation. These examples include comblike spectra [43][44][45][46] and the dependence of the comblike spectra on the phase between the polychromatic components [47][48][49][50][51]. The selective elimination of spectral lines is achievable by the polychromatic phase control.…”

Periodically driven facilitated high-efficiency dissipative entanglement with Rydberg atoms

“…From Eq. (9) and Fig.2(b) it is obvious that the presence of modulation ω can add frequency sidebands to the base frequency ω 0 which is also the characteristic frequency of system, giving rise to the multiple frequencies ω n = ω 0 ± nω with n = 0, 1, 2..., symmetrically located with respect to ω 0 [51]. As ω increases the dynamics become regular with one dominant base frequency ω 0 because a highmodulation-frequency ω will cause an average cancellation to the accumulated quantity by the frequency modulation |(ω 0 /2ω) sin(2ωt) t→∞ | → 0 as ω ≫ ω 0 .…”

Resonant light scattering of a laser frequency comb by a quantum dot

“…Ficek et al have analyzed the fluorescence spectrum of a two-level atom driven by a modulated field in which the central component's frequency coincides with the atom's natural transition frequency, and broadening is determined by spontaneous emission [38]. We extend their treatment to the calculation of the power spectrum and second-order correlation functions with detuning and spectral diffusion, and investigate the scattered-light correlations for the case when the multichromatic field is that of a short pulsed laser excitation (Fig.…”