“…In fact, the strong absorption and light scattering inherent in surface plasmon excitation has been used for thousands of years through the incorporation of metal particles in glass to create colorful stained glass windows and goblets [1]. More recently, surface plasmonbased photonics, or "plasmonics" [2][3][4], has been used for enhancing light-matter interaction at the nanoscale in controlling light propagation [5,6], emission [7,8], and concentration [9,10]. Research on plasmonics has become a flourishing field with numerous applications [11,12], including metamaterials and metasurfaces [13,14], sub-diffraction-limited imaging [15], lasers [16], and cloaking [17].…”