Chinese Physics Letters

Coherent Control of Absorption Resonances via Antirotating Coupling

Xiu Zhang, Guangling Cheng, Xiangming Hu

Published Jun 28, 2006• 0 citations

Abstract

Effects of the antirotating coupling on the absorption resonances are presented for a microwave driven three-level system. It is shown that nonlinear sideband generation, selective suppression and switching between peaks and dips in the absorption spectrum are obtained as the microwave Rabi frequency is varied. A physical explanation is given in terms of the coherent superposition of an infinite set of transitions that are associated with an infinite set of dressed states, which are created by the rotating and nonrotating couplings as the equivalent bichromatic excitation.

DOI: 10.1088/0256-307x/23/7/030

Related papers

Microwave control of optical bistability and multistability in the presence of antirotating wave coupling

Xiaoqi Li, Jian Wang, Wang Fei +2 more

We show the control of optical bistability and multistability via the atomic coherence induced by the microwave field in the presence of the antirotating wave coupling. Appearance or disappearance of bistability and multistability， manipulation of the hysteresis hoop widths and the threshold intensity are achieved by changing the initial phase of the microwave field. Physically， the rotating wave and antirotating wave couplings can be treated as the equivalent bichromatic excitation. Each of the coupled levels are split into an infinite set of sublevels. As a consequence， each of the bare state transitions is split into an infinite set of transitions of different frequencies. The coherent superposition of these split transitions， which depends on the initial phase of the microwave field， determines the nonlinear absorption and dispersion of the medium.

Acta Physica SinicaJan 1, 20082 citations

Counter-Rotating Transition Mediated Coherent Effects in Spontaneous Emission in a Three-Level Atom

Jun Xu, Xiangming Hu

The coherent effects including counter-rotating coupling on spontaneous emission are presented for a microwave driven V-type three-level atom. Novel coherent effects are realized: (i) There is an infinite series of spectral lines, which are separated by the microwave frequency, independent of the separation of the excited states, no matter whether the microwave transition is resonant or not. This is in sharp contrast to the case of the weak coupling, where the spectral interval is mainly determined by the separation of the excited states. (ii) Selective appearance and inhibition of the spectral lines are obtained simply by varying the microwave Rabi frequency. (iii) Spectral lines have a twofold structure. The physical mechanisms are analysed by employing the dressed states representation.

Chinese Physics LettersSep 27, 20061 citation

Quantum coherence in Λ-three-level system driven by bichromatic coupling field

Yang Li-Jun, Zhao Min, Lianshui Zhang +3 more

We present a theoretical study of quantum coherent effects in a Λ-three-level system with a strong bichromatic coupling field and a weak probe field. When one component of the strong bichromatic coupling field is resonant with a corresponding transition and the other is detuning with an integer fraction of the Rabi frequency of the resonant field, the absorption spectrum exhibits a series of symmetrical doublets. While two frequencies of the strong bichromatic coupling field are symmetrically detuned from the transition, the position and the relative intensity of the absorption peak are both affected by the coupling field intensity and detuning. An explanation of the spectrum is given in term of the dressed-state formalism.

Chinese Physics BAug 1, 20103 citations

Control of spontaneous emission from a micro-wave driven atomic system

Chun Liang Wang, Zhi Hui Kang, Si Cong Tian +1 more

We demonstrate coherent control of spontaneous emission from an indirectly coupled transition in a microwave driven four-level atomic system. The transition of concern is not directly coupled by any laser fields, while the ground state is coupled to another ground state by a microwave field. We show that the coupling of the microwave field produces interesting features such as double narrow lines in the emission spectrum. The heights, widths and positions of the emission peaks can be controlled by modifying the Rabi frequency and detuning of the microwave field. We discuss the spectra in the dressed states basis.

Optics ExpressJan 30, 201212 citations

On negative dispersion without absorption in bichromatically driven two-level systems

Carsten Szymanowski, Andreas Wicht, K. Danzmann

The possibility of obtaining strong negative dispersion without absorption in the central resonance structure of the spectrum of a bichromatically driven two-level system is investigated. A nonlinear analysis is performed using the technique of continued fractions with respect to the dressedstate basis of a strong pumping laser. We discuss the transition between the two regimes of the monochromatic driving case with a weak probing laser and of nearly equally strong lasers in terms of the contributions from coherences and populations of these dressed states. In contrast with the strong dependence of the Rabi side bands on probe field intensity, we find a remarkable stability of the negative dispersion in the central resonance structure.

Journal of Modern OpticsJul 1, 199714 citations

Dynamics of a driven two-level atom coupled to a frequency-tunable cavity

Peng Zhou, S. Swain

A cavity-modified master equation is derived for a coherently driven two-level atom coupled to a single-mode cavity in the bad cavity limit, in which the cavity frequency is tuned to either the center or one of the sidebands of the Mollow triplet. The atomic populations in both the bare- and dressed-state representations are analyzed in terms of the cavity-modified transition rates. In the bare-state basis, the role of the cavity may be interpreted as enhancing the stimulated absorption of the atom while suppressing the stimulated emission. The bare-state population may thus be inverted under appropriate conditions. The dressed-state inversion, however, originates from the enhancement of the atom-cavity interaction when the cavity is resonant with the atomic dressed-state transition. We show that two-phase quadratures of the atomic polarization decay at different rates. The decay of the in-phase (or out-of-phase) quadrature may be greatly inhibited as the driving intensity increases, depending on the cavity resonant frequency. The spectrum of the atomic fluorescence emitted out the side of the cavity is also studied. The spectral profiles are sensitive to the cavity frequency. When the cavity frequency is tuned to the center of the Mollow resonances, the fluorescence spectrum is symmetrical with three peaks whose linewidths and heights are intensity dependent. When the cavity frequency is tuned to one of the Mollow sidebands, however, it is asymmetric, and the central peak and the sideband on resonance with the cavity can be significantly suppressed for strong driving fields. All three spectral lines can be narrowed by increasing the Rabi frequency. The physics of these striking spectral features is explored in the dressed-state basis. We also investigate the probe absorption spectrum. When the cavity frequency is tuned to the center of the Mollow fluorescence triplet, the central component exhibits a Lorentzian line shape, while the side bands show the Rayleigh-wing line shape. Probe gain may occur at line center due to cavity-induced, bare-state population inversion. When the cavity is tuned to resonance with one sideband, only two sidebands, with Lorentzian profiles, dominate. Gain can occur at the sideband far off resonant with the cavity. The sideband gain is a consequence of an unbalanced dressed-state population distribution.

Physical Review AAug 1, 199835 citations