Tunable optical metasurfaces enabled by chalcogenide phase-change materials: From the visible to the THz - Ruiz de Galarreta C; Carrillo SGC; Au YY; Gemo E; Trimby L; Shields J; Humphreys E; Faneca J; Cai L; Baldycheva A; Bertolotti J; Wright CD (Journal Of Optics, 2020)