Inhomogeneous localization of nanoplasmonic eigenmodes. (a) Calculated local optical fields inside a fractal nanocluster made of silver nanospheres. Insert: geometry of such a cluster. (b) Surface plasmon eigenmodes for a semicontinuous metal nanofilm plotted against their oscillator strength and localization radius. The yellow background marks the bright (luminous) eigenmodes, the blue background highlights the strongly localized eigenmodes. (Adapted from Ref. ). (c) Schematic of experimental observation of the surface plasmon local fields. (From Ref. ). (d) Measured normalized variance of the decay rates of the dye molecule fluorescence. (From Ref. ). The red dashed vertical line qualitatively shows the onset of the significant fractality of the underlying metal clusters.