Ultrafast fluorescence parametric amplification for femtosecond molecular dynamics research

Abstract

This chapter investigates the application of parametric amplification in the field of ultrafast fluorescence dynamics. A new process is designed in which weak seed signals are amplified up to 107 times, and the temporal and spectral characteristics at the output are maintained. Optical parametric processes are widely used for tunable light sources in the visible and infrared ranges. Two typical systems are the optical parametric oscillator (OPO) and optical parametric amplifier (OPA) systems. With the development of table-top Ti:sapphire chirped pulse amplification laser systems, OPA systems have become widely employed. Their cavity-free design makes their alignment quite flexible and wavelength tuning easy. The broadband output can also be obtained. Compared to widely used OPO/OPA systems, the major issue is linearity in amplification instead of stability of the light source output. Two factors are taken into account for this purpose: seed intensity and pump energy.