This behavior is elaborated further in Figure (a), which shows maximum abs , sca , ext at resonance wavelength plotted as a function of SiO 2 insulator thickness. The absorption cross-section abs rises until = 30 nm, but starts to decrease when thicknesses of SiO 2 are increased further. At the same time, the scattering cross-section sca continues to increase up to a considerably higher = 150 nm SiO 2 thickness. As shown in Figure , at maximum extinction = 1 -, the absorption cross-section abs is likewise at its peak, yet the absorption/scattering cross section ratio = abs / sca at best becomes equal to 1.