Abstract

With the advent of reliable ultrafast laser apparatus the observation of the rotational dynamics of small molecules in the time domain has become feasible. A polarization selective transient grating (TG) setup with subpicosecond resolution allows to discriminate the nuclear optical Kerr effect (OKE) with respect to other physical processes in the sample due to the different symmetry of the associated nonlinear susceptibility tensors χ⁽³⁾ [1,2]. With this experimental approach we have studied the reorientational dynamics of neat biphenyl (BP) and pentylcyanobiphenyl (5CB) as well as solutions of these compounds in n-heptane over an extended temperature range.

© 1990 Optical Society of America