Active Nanophotonics: Surface Polariton‐Like s‐Polarized Waveguide Modes in Switchable Dielectric Thin Films on Polar Crystals (Advanced Optical Materials 5/2020)

In the field of nanophotonics, the active manipulation of light is facilitated by polaritonic modes in nanoscale heterostructures. In their article number 1901056, Nikolai Christian Passler, Alexander Paarmann and co‐workers present a switchable optical‐waveguide system that features four distinct polaritonic modes with high spectral contrast. The cover image illustrates the concept: a thin film on a polar crystal substrate can be switched between its amorphous and crystalline state, each supporting two differently polarized modes.