Abstract:
In a gas-phase ensemble at room temperature, molecules are, in an average, flying away by a few hundred meters, making turns almost reaching to 1011 times, and shaking themselves more than 1013 times within the duration of only one second. Our ultimate goal is to capture the lively figures of molecules moving in such a dynamic manner and to have a perfect command over the molecular motions.
When a gaseous molecular sample is irradiated by an intense nonresonant ultrashort laser pulse, the rotation and vibration of the molecules are coherently excited to create nonstationary quantum states of motion, i.e., quantum wave packets (WPs). We developed a method to explore such nonadiabatic rotational/vibrational excitation in a quantum-state resolved manner and applied it to several molecules and molecular clusters. In addition, we designed and constructed a new 2D imaging apparatus, which allows us to track the spatiotemporal evolution of coherently rotating/vibrating molecular ensembles.
In this presentation, I will describe some details on the above-mentioned two approaches adopted in our research group. I will also show several recent results, in particular, on the multi-pulse control over rotation/vibration coupling and application of the WP imaging to high-resolution time-domain spectroscopic studies on nonpolar molecular systems.