Subpicosecond laser spectroscopy: strong field effects on molecular photophysics and dynamics

The possible role of strong field effects is discussed in the context of picosecond relaxation and reaction in polyatomic systems. The picosecond pulse diagnostics from an argon-ion synchronously pumped dye laser are then outlined in terms of cavity detuning and laser pumping parameters. A profile of auto-correlation data on ensemble-averaged pulses and streak camera data on single pulses is presented, from which the domain of stable, single pulse operation can be deduced. Finally data are presented on the photoionization and energy relaxation of pyrene in alcohols and micelles, and for the reorientational dynamics of liquid chlorobenzene, which illustrate different consequences of strong field phenomena in dense media.