Physicists observe amplification of an optical signal within cubic nonlinear nanostructures for the first time

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.

Caption (Left) A scheme of nonlinear interaction of a plasmonic pump and localized, and, as a result, Stimulated Raman Scattering occurs; (right) A plot of scattered intensity vs the pump power. 

More information:
Sergey S. Kharintsev et al, Nonlinear Raman Effects Enhanced by Surface Plasmon Excitation in Planar Refractory Nanoantennas, Nano Letters (2017). DOI: 10.1021/acs.nanolett.7b02252

Provided by Kazan Federal University