Plasmons are resonant modes that entail the interaction amid free charges and electromagnetic waves. Their oscillation originated from the restoring force that the distorted charge distribution applies on the mobile charges as soon as they are dislocated from the equilibrium state. Surface plasmon modes can be localized in space in some nano-structured surfaces or around nanoparticles, with fields confined to a sub-wavelength dimension. The absorption of the visible light through plasmon resonance cause the change of the color of micro and nano-structured materials. For instance, Although the gold film has brilliant shiny yellow color, gold nanoparticles appears red.
Though the perception of plasmonic has drawn the attention of scientists and physicists mainly in 20th century, it has been in use since the first millennium BC when ancient civilizations made use of them for decoration and artistic purposes. A glimpse at the old colored (stained) glasses (e.g. the Roman Lycurgus cup and stained glasses in churches), colorful statues (e.g. the mask of the Tutankhamen’s mummy), painted tiles (the Immortal Soldiers at the Darius’ palace in Susa (see the photo) and the Ishtar Gate in Babylon) one can observe the range of different colors (blue to red) mainly arose from different metal/metal oxides particles embedded in a dielectric (ceramic) matrix. The colorful facades of the mentioned ancient sculptures might not be only plasmon originated but also the existence of metal/metal oxide particles in their top surface is one of the major reasons of their charming color.
Jaber-ibn-Hayyan, prominent Iranian chemist, was one of the first researchers who wrote a unique treatise of technical recipes dealing with the manufacture of colored glasses, making lustre-painted glass (stained glass) and coloring gemstones in the late 8th century. Recent chemical and microscopic analyses of a selection of lustre ceramics dating from the last quarter of the 10th century AD to the second half of the 13th century AD from Iran, Egypt and Syria as well as those of the 13th century Spanish lusters proved the existence of copper, gold and silver nanoparticles (NPs) as the main coloring components.
Plasmonic color nowadays are being furthe developed as “Metasurface structural color“.