An electronic excitation of a molecule by a sequence of two femtosecond phase-locked laser pulses is considered. In this case interference takes place between the vibrational wave packets induced by each of the subpulses within a single molecule. It is shown that, due to the dynamical squeezing effect of a molecular vibrational state, this interference allows one to measure the duration of a femtosecond laser pulse. This can be achieved experimentally by measuring the dependence of the integral fluorescence of the excited molecule on the delay time between the subpulses. The interference can lead to a sharp peak (or to a dip) in that dependence, the width of which is equal to the duration of the laser pulse. It is shown that a finite temperature of the medium is favourable for such an experiment.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering