Anomalous dispersion and negative group velocity in a coherence-free cold atomic medium
نویسندگان
چکیده
منابع مشابه
Transparent anomalous dispersion and superluminal light-pulse propagation at a negative group velocity
Anomalous dispersion cannot occur in a transparent passive medium where electromagnetic radiation is being absorbed at all frequencies, as pointed out by Landau and Lifshitz. Here we show, both theoretically and experimentally, that transparent linear anomalous dispersion can occur when a gain doublet is present. Therefore, a superluminal light-pulse propagation can be observed even at a negati...
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In more detail, consider a classical model of matter in which spectral lines are associated with oscillators. In particular, consider a gas of atoms with two closely spaced spectral lines of angular frequencies ω1,2 = ω0 ± Δ/2, where Δ ω0. Each line has the same damping constant (and spectral width) γ. Ordinarily, the gas would exhibit strong absorption of light in the vicinity of the spectral ...
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ژورنال
عنوان ژورنال: Journal of the Optical Society of America B
سال: 2008
ISSN: 0740-3224,1520-8540
DOI: 10.1364/josab.25.000c82