Strong molecular alignment in anisotropic fluid media

Picosecond polarised fluorescence studies of rhodamine 6G molecules in a 100 μm free ethylene glycol jet show the production of strong molecular alignment with a degree of ordering between one to two orders of magnitude greater than that attainable for similar systems using conventional fluid alignment techniques. Using a novel variation of the polarised picosecond single-photon counting technique, it has been possible to prepare a range of non-equilibrium molecular orientational distributions in the jet and observe their subsequent evolution. The imposition of order in the flow is seen to have a distinct effect on molecular motion, indicating a strong anisotropy in θ and /gf rotational diffusion dynamics.