Figure 3: Extinction and transmission phase of an isolated ring-disk dimer.

(a) Extinction of the ring-disk dimer for various excitation polarizations by 20° step (red curve is along the long axis of the dimer and dark blue curve is along the short axis of the dimer direction). The black line is a best fit of the oscillator model with one bright and two dark modes. (b) Transmission phase of the dimer for the various excitation polarizations by 20° step corresponding to the extinction spectra shown in a. The phase of the oscillator model fit in a is shown in black. The vertical black dotted lines indicate the location of the dark modes of the ring. (c) Response functions for the bright (orange) and dark (cyan) modes used in the oscillator model fit (black). The charge distributions of the structure at the Fano dips are shown in insets (See Methods). (d) Extinction for the individual ring and disk constituents of the dimer. The arrows indicate the location of the dark modes. Note that saturation of the spectral response near 810 nm due to the supercontinuum light source was removed.