High-Q resonances in one-dimensional arrays of dipolar scatterers

In this work, we study dipolar oscillations in infinite and finite one-dimensional arrays of scatterers supporting dipole resonances. We show that the presence of two dipolar responses of different types in a single scatterer can induce a change of the dispersion of an infinite chain from monotonic to non-monotonic one. In turn, the non-monotonic dispersion leads to the interaction between two collective modes in the corresponding finite chain. This results in a strong suppression of the radiative losses of one of the modes for a certain distance between the scatterers. Moreover, by tuning the ratio of the resonant frequencies in a single scatterer the optimal period can be shifted to the values that can be realized in feasible optical designs.