A new method for optically exciting and visualizing surface plasmons in thin metal films is described. The technique relies on the use of a high-numerical-aperture objective lens to locally launch a broad wavelength spectrum of surface waves and to detect the leaky radiative modes associated with them. We used this approach to obtain a direct visualization of the plasmon intensity distributions, e.g., rainbow jets, and to quantify their propagation lengths throughout the visible spectrum.
© 2005 Optical Society of America
A. Bouhelier and G. P. Wiederrecht, "Surface plasmon rainbow jets," Opt. Lett. 30, 884-886 (2005)