TEM images and XRD pattern; schematics describing experimental setups for measuring time-dependent absorbance and ensemble fluorescence anisotropy; additional optical response and ensemble anisotropy data measured using an alternate batch of CdSe/CdS NRs; overhead images of UV-illuminated sample cell with and without an external AC field; plot of average deviation angle vs focus factor (𝜅); derivation of theoretical expression for ensemble fluorescence anisotropy (PDF) M.T.S. and R.J.R. conceived the idea. R.J.R., F.A.R.O. and N.J.G. designed and conducted the experiments. R.J.R. and F.A.R.O. performed characterization. R.J.R. derived the theoretical equations. R.J.R., F.A.R.O. and M.T.S. wrote the manuscript. All authors reviewed the manuscript.