Phase sensitive pump-probe spectroscopy using a Michelson-type interferometer

Time-resolved phase sensitive pump-probe spectroscopy using a Michelson-typ e interferometer has been carried out. In this experiment, we obtain inform ation on the time-resolved amplitude and phase of probe pulses by measuring cross-correlations between probe pulses and reference pulses. This method was demonstrated in an experiment on dye molecules, hexamethylin-dotricarbo cyanine iodide, in ethylene glycol at room temperature. The experimental re sults indicated the time evolution of the phase and the increase in peak ve locity of the probe pulse. These phenomena can be explained by phase veloci ty change and group velocity change due to thr pump pulse. A simulation bas ed on a two-level Bloch model for the dye molecules reproduced the experime ntal results quite well.