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Pulsed light beams in vacuum with superluminal and negative group velocities

M. A. Porras·I. Gonzalo·A. Mondello
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Abstract

Gouy's phase of transversally limited pulses can create a strong anomalous dispersion in vacuum leading to highly superluminal and negative group velocities. As a consequence, a focusing pulse can diverge beyond the focus before converging into it. A simple experiment is proposed.

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M. A. Porras, I. Gonzalo, A. Mondello. 2002-02-27. Pulsed light beams in vacuum with superluminal and negative group velocities. https://doi.org/10.1103/physreve.67.066604

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