Upon transmission of an optical pulse through a finite-size photonic band g
ap structure, along with a strong attenuation and an apparently superlumina
l propagation of the maximum of intensity, a shortening of the pulse durati
on has been observed in experiment and numerical simulation of the interact
ion between a wave and matter. To give an explanation for this observation,
a simplified model for the spectral transmission properties of a 1D band g
ap structure (dielectric mirror) is analyzed. The results are compared to t
he shortening of numerically obtained temporal pulse profiles. (C) 2000 Els
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