Spontaneously generated coherence effects in a laser-driven four-level atomic system

Journal Article · Mon Aug 15 04:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.72.023809· OSTI ID:20718208

Anton, M A; Calderon, Oscar G; Carreno, F ^[1]

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1. Escuela Universitaria de Optica, Universidad Complutense de Madrid, C/Arcos de Jalon s/n, 28037 Madrid (Spain)

In this paper we investigate the resonance fluorescence, the squeezing, and the absorption spectra of a laser-driven four-level atom consisting of three closely spaced upper levels decaying to a common lower level. The three upper levels are coupled by the same vacuum modes to the lower level leading to spontaneously generated coherence effects. High population inversion and extremely narrow emission lines are obtained with moderate Rabi frequencies, which are a direct consequence of decay-induced interferences. The fluorescent field is shown to exhibit two-mode squeezing in the in-phase quadrature. Squeezing in both quadratures simultaneously at different frequencies is greatly enhanced when quantum interference is accounted for. We also examine the absorption spectrum of a weak field and demonstrate that quantum interference can induce two prominent and nearly transparent holes where the slope of the refractive index is very steep. This special situation could allow the simultaneous propagation of two weak pulses with different frequencies, which could be feasibly exploited towards the realization of the entanglement of two photons.

• OSTI ID: 20718208
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 72; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION SPECTRA
ATOMS
DECAY
ENERGY LEVELS
HOLES
INTERFERENCE
LASER RADIATION
PHOTON-ATOM COLLISIONS
PHOTONS
POPULATION INVERSION
PULSES
QUADRATURES
QUANTUM ENTANGLEMENT
REFRACTIVE INDEX
RESONANCE FLUORESCENCE