Plasmonics

Article By:

Pang, Lin Ultrafast and Nanoscale Optics Group, Department of Electrical and Computer Engineering, University of California, San Diego, California.

Fainman, Yeshaiahu S. Ultrafast and Nanoscale Optics Group, Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California.

Last reviewed:2014

DOI:https://doi.org/10.1036/1097-8542.YB140219

Plasmonics, the study of optical resonance in metallic nanostructures, was unknowingly used hundreds of years ago by alchemists and glassmakers to make stained-glass windows and colorful goblets that incorporated various small metallic particles into the glass. The various colors exhibited in the glass matrix are the result of the nanometallic particles in the glass scattering different wavelengths of light. How the light is scattered depends on the size and shape of the particles because of the plasmonic resonance of a metal, which is generated by the collective movement of free electrons in response to incident light waves. One form of the excited plasmons, called the localized surface plasmon resonance, depends strongly on the nanoscale size, shape, and specific metal material. A consequence of this resonance is that the local electric field is enhanced by several orders of magnitude compared to the electric field associated with the incident optical field. Another form of the plasmonic resonance is generated at the surface of a metallic film: The excited collective oscillations of the free electrons follow the momentum of the incident wave traveling on the metallic surface, called the propagating surface plasmon resonance.

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