Wave Packet Interferometry and Other Applications of Phase Locked Femtosecond Pulses

The ability to control the relative optical phase of ultrashort light pulses [1] as well as their duration and time delay [2] offers new capabilities for the study and manipulation of molecular responses. We have recently reported a new experimental method for setting and maintaining the relative optical phases within a sequence of ultrashort light pulses [1]. The initial studies involved fluorescence detected interfermotry measurements on iodine vapor. These measurements were shown to be extremely sensitive to the transition energies and potential energy surface of the excited state. The experimental interferograms have been analyzed in detail and the effect of rotational motion elucidated. By extending the technique to in-quadurate phase-locked pulses a relationship between the interferograms and the linear susceptibility to be obtained directly.