“…An ensemble of metallic nanostructures arranged in a periodic pattern is capable of supporting collective modes known as lattice resonances. − These modes are the direct consequence of the regular arrangement of the array, which enables the coherent multiple scattering between the optical responses of the individual constituents . Lattice resonances appear at wavelengths that match the periodicity of the array − and, thanks to their collective nature, exhibit strong optical responses with lineshapes much narrower than those associated with the individual nanostructures composing the array. − In particular, arrays supporting lattice resonances can reach values of reflectance and absorbance that saturate the theoretical limits − , with quality factors well beyond one thousand. − At the same time, they produce very strong near-field enhancements, , only limited by the number of elements of the array that are coherently coupled . As a result of their exceptional properties, lattice resonances are being explored for the development of different optical systems such as color filters, , lenses, light-emitting devices, − and chiral elements, − as well as ultrasensitive biosensors, − light-to-heat transducers, , and even platforms to mediate long-range energy transfer, − strong coupling, , or to achieve Bose-Einstein condensation. , …”