(including both homogeneous and inhomogeneous broadening) propagate with low energy loss. The results are explained in terms of simple physical arguments which indicate that the pulse envelope should oscillate between positive and negative values, causing the area to decrease without a comparable decrease in the pulse energy. Analytic solutions are presented for the case of a pulse whose envelope varies as

{t}^{k}{e}^{\ensuremath{-}t}

for

tg0

, a rectangular pulse, an ultrashort pulse (i.e., pulse width much less than

{T}_{2}

), and the leading portion of a step-function pulse. The propagation of a small-area Gaussian pulse is studied numerically.

DOI: 10.1103/physreva.2.2172.2

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Propagation of Small-Area Pulses of Coherent Light through a Resonant Medium

Michael D. Crisp

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Superradiant Effects on Pulse Propagation in Resonant Media

Antonio M. Ponte Goncalves, Andree A. Tallet, R. Lefèbvre

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Dec 14, 20110 citations

{T}_{2}

{t}^{k}{e}^{\ensuremath{-}t}

for

tg0

, a rectangular pulse, an ultrashort pulse (i.e., pulse width much less than

{T}_{2}

), and the leading portion of a step-function pulse. The propagation of a small-area Gaussian pulse is studied numerically.

{T}_{2}

t>0

, a rectangular pulse, an ultrashort pulse (i.e., pulse width much less than

{T}_{2}

), and the leading portion of a step-function pulse. The propagation of a small-area Gaussian pulse is studied numerically.

{\mathrm{T}}_{2}

. It is shown that if ${\mathrm{\ensuremath{\tau}}}_{\mathrm{band}}$ is the same order or smaller than

{\mathrm{T}}_{2}

, the reshaping (oscillations) of the pulse envelope and/or low energy-loss effects occur in accord with the general conclusions pointed out by Crisp [Phys. Rev. A 1, 1604 (1970)] in the case of the SAP for coherent light traveling through a resonant medium. The experimental conditions for the observation of penetration effects of the SAP of x rays are discussed. Based on the theoretical study, it is found that an ultrashort x-ray pulse emitted by an ultrashort laser-produced plasma propagates through thin resonant medium foils with low energy loss.