High-<i>Q</i> Localized States in Finite Arrays of Subwavelength Resonators

We uncover how to achieve giant Q-factors in finite-length periodic arrays of subwavelength optical resonators. The underlying physics is based on interference between the band-edge mode and a standing array, it leads formation spatially localized states with dramatically suppressed radiative losses. demonstrate this concept for an array N dipoles simultaneous cancellation multipoles up N-th order Q-factor growing as Q ? N?, where ? ? 6.88. study realistic nanoparticles (N ? 37) supporting magnetic dipole Mie resonances enhanced Purcell factor (?7600) achieved by tuning parameters.