A PROPOSITION OF A NEW TYPE OF FEMTOSECOND TRANSIENT SPECTROSCOPY FOR UNIQUELY DETERMINING CLASSICAL TRAJECTORY

We demonstrate theoretically that the trajectory of the mean packet position can be extracted by a new type of transient spectroscopy in which the probe is not pulsed but continuous. Time resolution is performed by measuring the instantaneous emission intensity from the state created by the probe. We manipulate a packet correlation function derived from the emission intensity to produce the (probe) spectrum provided by the classical Franck-Condon principle. The phase given by the ratio of the absorption part of the artificial spectrum to the dispersion part uniquely determines, as a function of time, the difference between the relevant two potentials at the mean packet position.