Relaxation of Large Molecules Following Ultrafast Excitation

摘要

We demonstrate that the ultrafast relaxation observed in the excited states of large organic molecules in solution may be understood as the coherent evolution of the initially prepared non-stationary state. It is shown that under femto-second excitation conditions the relaxation is determined by the characteristics of the light pulse. The analysis of a simple pump-probe experiment suggests a way of measuring the characteristics of ultrashort pulses. The case of fluorescence excited by ultrafast pulses is also analyzed.