where 𝑐 is the concentration, 𝑙 is the path length, and 𝜎 G is the average attenuation cross-section. This formalism can be adapted to calculate the absorbance of an ordered ensemble of NRs or NR bundles considering the angledependent absorption cross-section of individual absorbers. If each particle behaves as an ideal dipole absorber, the attenuation crosssection (𝜎) of an arbitrarily oriented absorber excited by linearly polarized light (along the X-Z plane in Figure ) is related to its zenith (𝜃) and azimuth (𝜑) angles according to eq 5: