| In this research we are probing the nematic liquid crystal 5CB for non-director mode fluctuations, namely the order parameter Q which indicates optical anisotropy, as proposed by Z. H. Wang and P. H. Keyes in Critical and Multicritical Fluctuations of Nematic Liquid Crystals (Phys. Rev. E, 54, 5249(1996)). By utilizing dynamic light scattering we are able to look at intensity fluctuations based on time rather than just magnitude. This is necessary because the director mode fluctuations are known to have intensities that dominate the other modes by a factor of 106. Utilizing this method we are able to pick up both the R and the Q signal despite the large signal intensity difference. This is significant because it is the first documented case of a non director mode fluctuation in a nematic liquid crystal. Also of note is the discovery of another non director mode fluctuation which could be related to an isotropic fluctuation but further investigation is needed. The angular and temperature dependence of the signals are analyzed and discussed. |
