A plasmonic metamaterial is a metamaterial that uses surface plasmons to achieve optical properties not seen in nature. Plasmons are produced from the interaction of light with metal-dielectric materials. Under specific conditions, the incident light couples with the surface plasmons to create self-sustaining, propagating electromagnetic waves known as surface plasmon polaritons (SPPs). Once launched, the SPPs ripple along the metal-dielectric interface. Compared with the incident light, the SPPs can be much shorter in wavelength.[1]
The properties stem from the unique structure of the metal-dielectric composites, with features smaller than the wavelength of light separated by subwavelength distances. Light hitting such a metamaterial is transformed into surface plasmon polaritons, which are shorter in wavelength than the incident light.