The coherent amplification of a localized optical signal within a planar titanium nitride nanoantenna has been achieved by scientists of Kazan Federal University (under the leadership of Sergey Kharintsev) and physicists from Harvard University, Nazarbayev University, and Imperial College London. The results have been recently published in Nano Letters.
"The observable phenomenon is based on the nonlinear interaction of surface plasmon-polaritons and localized Stokes wave", explained Dr. Kharintsev. "Stimulated Raman (gain) emission and (loss) absorption of light are generated within a planar TiN nanoantenna exposed to a continuous laser wave with a modest power".
According to the physicists, these results will contribute to the development of a novel area in material sciences, in which plasmonic, Raman-active, and refractory materials are studied for amplifying optical signals beyond the diffraction limit of light.