Professor Albrecht is supported by the Experimental Physical Chemistry Program to develop and characterize novel nonlinear optical techniques and to apply these techniques to the study of ultrafast dynamical processes in a variety of molecular liquids. Two complementary four-wave mixing techniques are used. One new approach uses nanosecond light pulses having a very short correlation time. Both precise frequency (even sub-Raman linewidth) and time measurements are possible, though on an "accumulated" basis. There is promise that inhomogeneous broadening can be separated from the homogeneous. The second four-wave mixing technique uses femtosecond multicolor pulses to measure time-resolved dynamics on the same systems. Processes that affect electronic, vibronic, and vibrational dephasing are examined either in molecular liquids and their mixtures or in solutions of dye aggregates.
