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Large negative and positive delay of optical pulses in coherently prepared dense Rb vapor with buffer gas

Eugeniy E. Mikhailov·Vladimir A. Sautenkov·Irina Novikova·George R. Welch
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Abstract

We experimentally study the group time delay for a light pulse propagating through hot Rb vapor in the presence of a strong coupling field in a $Λ$ configuration. We demonstrate that the ultra-slow pulse propagation is transformed into superluminal propagation as the one-photon detuning of the light increases due to the change in the transmission resonance lineshape. Negative group velocity as low as -c/10^6=-80 m/s is recorded. We also find that the advance time in the regime of the superluminal propagation grows linearly with increasing laser field power.

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Eugeniy E. Mikhailov, Vladimir A. Sautenkov, Irina Novikova, George R. Welch. 2004-02-18. Large negative and positive delay of optical pulses in coherently prepared dense Rb vapor with buffer gas. https://doi.org/10.1103/physreva.69.063808

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