Effect of temporal fluctuations of the optical path in a system for data storage by cumulative photon echo

An investigation is made of the efficiency of repeated excitation of a sample by laser pulse pairs when data are stored by the photon echo method. Fluctuations of the difference between the pulse phases in different pairs, resulting from instability of the optical path length in the delay line, are shown to prevent cophasal superposition of a set of level-population gratings. The possibility of weakening the negative influence of this effect on the intensity of the read echo signal is considered.