When electromagnetic radiation is fired at a metal surface, quite a lot of it is reflected. The reflected beam’s intensity can be easily measured. At a particular angle of incidence and specific frequency a large amount of energy is absorbed by the surface electrons of the metal and causes them to resonate. When this happens they are called surface plasmons and the intensity of the reflected beam drops as a result of the beam’s energy going to these electrons instead. The resonant frequency of these plasmons are closely related to their surroundings and so information about the material can be gathered through this method.
There has been a recent paper published talking about the possibility to use plasmonic imaging in metal microstructures to learn about their exact layout. Since these structures are approaching the size of the wavelengths that resonate with the electrons sometimes only one plasmon is formed. Sometimes these structures are small enough to be nanodimers, just two nanoparticles of metal that remain in close proximity to each other. This paper has shown the importance of a single plasmon model and also theoretically how the unstabable plasmons could be maintained by pulsed excitation. Under normal circumstances the resonance of the electrons is damped quite heavily as soon as the electromagnetic radiation is removed. This could lead to further experimental research with new possibilities for plasmonics in sensing equipment.