One-click electromagnetism at the nanoscale
A thin layer of sub-wavelength particles arranged on a surface to shape light: its reflection, transmission, phase or polarization. Arrays of plasmonic or high-index dielectric particles are the simplest metasurfaces; their collective lattice resonances and Mie resonances are what this calculator computes. More in metasurfaces and lattice resonances.
In a periodic array, each particle's resonance couples to light diffracted along the array (the Rayleigh anomaly, at a wavelength near period × refractive index). The result is a narrow, strong collective resonance, much sharper than a single particle's.
Exactly, for an infinite array: each sphere's T-matrix is coupled to all the others through Ewald lattice sums, with or without a substrate.
Lattice resonances need the same refractive index above and below the array; a substrate breaks this symmetry and weakens or splits them. The calculator includes the substrate's reflections exactly.
Periodic arrays of spheres on or off a substrate: lattice resonances and near fields, in one click.