Optically-heterodyne-detected optical Kerr effect (OHD-OKE): Applications in condensed phase dynamics

The ultrafast optically-heterodyne-detected optical Kerr effect (OHD-OKE) is established as a relatively simple tool for recording the ultrafast dynamics of liquids with high temporal resolution and excellent signal-to-noise ratios. The principles and practice of the OHD-OKE method are outlined. Its application in recording the dynamics of several molecular liquids is described. The data are discussed in terms of the underlying microscopic molecular motions. Orientational motion--both librational and diffusive--is responsible for a significant fraction of the dynamics. Other potential contributions are discussed, but these are less readily assigned. The application of OHD-OKE measurements in interpreting ultrafast studies of the optical dynamics of solutions is discussed. Finally the extension of OHD-OKE methods to record the dynamics of more complex, heterogeneous, media is described.