ABOUT NEW METHOD OF HIGH HARMONIC AMPLIFICATION

摘要

We have demonstrated, that the temporal shift between pump and probe waves essentially violates the symmetry between processes of stimulated emission and absorption. This gives rise to the occurrence of the appreciable amplification of the probe wave of HH. It is shown that the gain is positive only if the probe wave is delayed with respect to the pump one and it may be substantial. Probable schemes for experimental observation of HH amplification will be discussed in details elsewhere. It should be stressed only that the weak probe wave may be obtained in the process of spontaneous HHG in the one atomic jet and directed to the second atomic jet with small temporal delay with respect to the pump pulse. In the second jet the amplification of this probe wave should be observed. Such experimental setup is very close to well-known cross-correlation experiment.