Measurements of the director fluctuations in nematics by speckle interference


  • Marek Wojciech Sierakowski Warsaw Univ. of Technology



Orientational fluctuations in nematics were experimentally investigated by homodyne speckle interference. Thermally excited fluctuations are local stochastic events. Such fluctuations in most cases relax in time aperiodically. In this experiment fluctuations were incidentally observed, and they could oscillate during some life-time before decaying. They were correlated spatially over an area of relatively large size. For convenience, large oscillating fluctuations, correlated in time and space, are called in this report "fluctuons". Usually, the fluctuons observed in the experiment had several oscillating cycles. An average lifetime of single fluctuons measured was a few miliseconds. The fluctuons have thermal origin but their average amplitude and probably also the correlation length could have been enhanced by electric DC, low frequency or optical field (in the linear range), even in the range below the re-orientational threshold intensity.

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How to Cite

M. W. Sierakowski, “Measurements of the director fluctuations in nematics by speckle interference”, Photonics Lett. Pol., vol. 2, no. 3, pp. pp. 122–124, Oct. 2010.