Propagation narrowing in the transmission of a light pulse through a spectral hole

We comment on the spectral modification and temporal reshaping of a narrow-band light pulse propagating through an atomic absorber that has a still narrower spectral hole. The regime of propagation narrowing is distinguished from the regime of Beer's law.Mr. Szabo was affiliated with the National Research Council of Canada, Division of Electrical Engineering, when they authored this article.M. Szabo \ue9tait affili\ue9 avec le Conseil national de recherches du Canada, Division de g\ue9nie \ue9lectrique lorsqu\u2019ils ont r\ue9dig\ue9 cet article.Peer reviewed: YesNRC publication: Ye