Generation of short laser pulses during coherent amplification

It is shown that when an n-pi pulse passes through a resonant-absorption medium it may efficiently transfer energy to a pulse at the frequency of an adjacent transition, and the length of the new pulse may be substantially smaller than that of the original n-pi pulse. An output intensity of greater than about a million W/sq cm, a quantum conversion efficiency of about 0.8, and a pulse of about 10 to the -12th s are obtained by the calculations.