Abstract

There are limited numbers of techniques which can directly observe surface plasmon (SP) in real space, because of difficulty in detecting SP in high spatial resolution on subwavelength scale. Recently we have developed a new technique using a 200kV transmission electron microscope (TEM) equipped with a light detection system, which has been known as TEM cathodoluminescence technique (TEM-CL). In this technique a focused electron beam is scanned on a metal surface containing nano-structures, and exciting SP on the metal surface. The excited SPP transforms to light, when propagating on surface structures. This technique has the following characteristics; (1) a point source of SPP can be generated at any position, (2) SPP propagates to every direction as 2-dimensional spherical wave, (3) SPP modes with energy up to the cut-off frequency are simultaneously excited.

© 2009 IEEE