Optically induced SHG as a probe of orientational dynamics in liquids

Abstract

We report the application of a resonant non-degenerate six wave mixing experiment to the measurement of ultrafast orientational dynamics in solution. Simultaneous excitation of the sample by a femtosecond pulse and its second harmonic leads to an anisotropic distribution of excited states, which supports SHG. It is shown that measurement of the SHG generated with a time delayed pulse yields a more detailed picture of orientational relaxation than is attainable from four wave mixing.