Pulse propagation in a one-atmosphere CO2 laser amplifier

The theoretical propagation of short laser pulses of 150 ps in a one-atmosphere CO2 amplifier is investigated using a fully coherent density matrix code. The influence of coherent effects and of the response times of the amplifying medium on the temporal shape of the output pulse is examined, and it is found that short pulses whose widths are approximately equal to the dipole dephasing time of the medium can be effectively amplified. The amplification is not efficient from an energy standpoint, although high peak powers and fast risetimes can be achieved.