M. Husnik, S. Linden, R. Diehl, J. Niegemann, K. Busch, and M. Wegener 

Phys. Rev. Lett. 109, 233902 (2012)

Abstract:

Antennas convert propagating radiation to localized electromagnetic energy and to heat. To unambiguously separate between these two aspects, one needs to quantitatively determine the antenna scattering and absorption cross-section spectra. By using a spatial modulation technique combined with a common-path interferometer and lithographically fabricated individual gold nanoantennas, we experimentally determine the scattering and absorption cross-section spectra of different optical antennas simultaneously and quantitatively for the first time.