Overall, these results support our hypothesis that the electro-optic response arises due to separate contributions from (1) the optical anisotropy of mesoscale NR assemblies that form in the absence of applied fields and (2) macroscopic ordering imposed by the electrostatic forces of the driving AC field. The greater magnitude of ∆𝐴 𝐴 ! ⁄ at higher NR concentrations is attributed both to an increase in the optical anisotropy of the emitting species, i.e., the formation of NR bundles, as well as a greater susceptibility of these bundles to field-driven ordering. While the magnitude of the experimentally measured ∆𝐴 𝐴 ! ⁄ in our study is comparable with previous reports 27 , our analysis indicates a significantly lower degree of maximum NR alignment. The disparity lies in our analysis of the role of individual absorbers. Instead of assuming colloidal NRs to be individual isolated particles, we treat them as aggregated bundles with varying degrees of characteristic concentration-dependent optical anisotropy.