Optical nutation and photon echo by phase or amplitude shift of light waves

Abstract

Optical nutation and photon echo caused by phase shift of a light wave incident on a resonant medium are considered. The case of simultaneous ultrashort perturbation of phase and amplitude is also treated. It is shown that a change of linear to circular polarization of incident light waves gives rise to an increase of the period and the decay time of optical nutation on the resonant atomic transitions J→J. On the contrary, the above mentioned period and decay time in the same situation are decreased on the resonant atomic transitions with the moment change J⇄J+1. This law in optical nutation can be taken as a base of the method for experimental identification of the atomic and molecular transitions. Moreover, the comparison of the theoretical and experimental optical nutation curves allows the probability of spontaneous emission to be determined.