Autoresonant Excitation Of Molocules

One of the main interests in the field of short pulses high intensity lasers is coherent control. This is an area of various methods whose purpose is to control the processes that occur in molecules and atoms. One important process is the passage between vibrational states. Controlling this process can help getting dissociation of selected atoms in molecules, as well as changing chemical reactions to get other products then usual.þ
We use the method of ladder climbing, which is the quantum equivalent to autoresonance, in order to raise vibration states into higher modes.þ Autoresonance is a nonlinear phenomenon which allows powerful driving force with adiabatic changing frequency that works on a perturbed system to capture it in to resonance. The system also stays phase locked with the driving force.þ

We use nonlinear optics in order to obtain chirped ultra wide-band radiation in the mid-IR. The spectrum is chirped negatively, while the chirp coefficient is adjusted to fit the ladder climb scheme.þ
We have succeeded to excite this way HF molecules to the third vibrational level.þ