Femtosecond Wavepacket Interferometry And Its Application

The femtosecond wavepacket interferometry has become a new technique to study quantum coherent progresses in the system with the rapid development of femtosecond laser technique and quantum coherent control theory. It can be widely applied in the photophysical, photochemical and photobiological processes, such as: manipulation of vibrational dynamics, one or multi photon transition, selective control of product formation in chemical reaction, and so on. So it is very necessary and important for us to investigate wavepacket interferometry technique and its application. In this thesis, we explain the principle of wavepacke interferometry, introduce a self-designed wavepacket interferometric system and investigate two-photon fluorescence signal by using the system to realize the interference between excited wavepackets.1) A self-designed wavepacket interferometric system is established with Michelson interferometer, photoelectric detector, server circuit system and piezoelectric transducer (PZT) to generate phase-locked laser pulse pairs.2) Utilizing the homemade wavepacket interferometric system, the wavepacket interferometry of two-photon transition process in complicated molecular system DCM (4-dicyanomethylene-2-methyl-6-p-dimethyl-aminostryryl-4H-pyran) is experimentally demonstrated. The interference phenomena between the excited wavepackets by phase-locked laser pulses are analyzed. The experimental results show that it is feasible for the self-designed wavepacket interferometric system to accurately control the phases of laser pulses.