Time Frequency analysis of Highly Nonlinear Molecular Processes
Yoshiaki Teranishi1*
1Institute of Physics, National Chiao Tung University, Hsinchu, Taiwan
* Presenter:Yoshiaki Teranishi, email:tera@mail.nctu.edu.tw
When an intense laser (intensity of ~10¹³ W/cm²) is irradiated in air, it is known that an interesting phenomenon called laser filamentation takes place, in which the laser intensity is kept for a long distance such as 10 Km. There have been various applications of this phenomenon, such as remote sensing, lightening control, and inducing rain/snow. In order to realize these applications, it is necessary to understand how molecules are excited by such intense lasers. Since the laser intensity is very strong, conventional perturbative approach does not work. In this talk we present our new theory of intense field excitation, combining the Floquet theory and the idea of nonadiabatic transition. It will also be shown that time-frequency analysis of transition amplitude can provide rich information of the Floquet state and the transitions among them.

Keywords: Intense laser field, Floquet theory, Nonadiabatic transition, Time-frequency analysis, Laser FIamentation