Plasmon is a quasiparticle or a quantum of plasma oscillations. According to the researchers, the effects arising from the surface interactions of electromagnetic waves with plasmons could bring about a breakthrough in high-accuracy electronics and optics. One possibility opened up by plasmonic effects is the subwavelength light focusing, which increases the sensitivity of plasmonic devices to a point where they can distinguish a single molecule.
This has led to the development of a quantum model that predicts plasmonic behaviour in graphene. As a result, the scientists have described a spaser – the nanoplasmonic counterpart of the laser — whose construction involves a graphene layer.
A spaser can be described as a device similar to a laser and operating on the same basic principle. However, to produce radiation, the spaser relies on optical transitions in the gain medium, and the particles emitted are surface plasmons, as opposed to photons produced by a laser.
‘The graphene spaser could be used to design compact spectral measurement devices capable of detecting even a single molecule of a substance, which is essential for many potential applications. Such sensors could detect organic molecules based on their characteristic vibrational transitions as the light emitted/absorbed falls into the medium infrared region, which is exactly where the graphene-based spaser operates,’ said researcher Alexander Dorofeenko.