Propagation of light pulses in a fast-light medium: Interplay between gain and dispersion
Résumé
We consider here the situation of a Gaussian pulse that probes a medium exhibiting two close resonance lines. We study the spatial behavior of the light pulse and emphasize some overlooked features. Moreover, for long pulses and a fast-light medium, we show that the spatial distortion of the pulse due to residual gain at the central laser wavelength cannot be reduced without enhancing another distortion effect due to spectral wing amplification.