In Fig. , the extinction spectra and the near-field distributions are averaged over x, y, and z polarizations and 10 gel configurations from independent MD simulations. The nearfield distributions are sampled at the frequency corresponding to maximum |⟨p⟩| for each gel. In Fig. , the perpendicular-polarization extinction spectra is averaged over two polarizations (E 0 êy and E 0 êz ) perpendicular to the elongation axis (ê x ), both the parallel-and perpendicular-polarization extinction spectra are averaged over 10 independent trajectories at each strain value, and ω LSPR is the frequency corresponding to the maximum value of the extinction spectra. These results are reported as dimensionless values