Reduction in the duration of small-area pulses during coherent propagation across an absorber

A study was made of coherent propagation of small-area pulses across a resonant absorber. At least five-fold reduction in the duration of subnanosecond pulses with a steep leading edge (τe ≲ 20 psec) was observed as a result of passage through a ruby rod cooled to 100 K. This reduction in the duration was due to the finite time needed to establish absorption. The experimental results were in agreement with a numerical solution of a system of Maxwell-Bloch equations describing the interaction of a field of a pulse with a resonant medium.