Hofmann Carrie E, Vesseur Ernst Jan R, Sweatlock Luke A, Lezec Henri J, García de Abajo F Javier, Polman Albert, Atwater Harry A
Thomas J Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA.
Nano Lett. 2007 Dec;7(12):3612-7. doi: 10.1021/nl071789f. Epub 2007 Nov 14.
We report the observation of plasmonic modes of annular resonators in nanofabricated Ag and Au surfaces that are imaged by spectrally resolved cathodoluminescence. A highly focused 30 keV electron beam is used to excite localized surface plasmons that couple to collective resonant modes of the nanoresonators. We demonstrate unprecedented resolution of plasmonic mode excitation and by combining these observations with full-field simulations find that cathodoluminescence in plasmonic nanostructures is most efficiently excited at positions corresponding to antinodes in the modal electric field intensity.
我们报告了通过光谱分辨阴极发光成像观察到的纳米制造的银和金表面环形谐振器的等离子体模式。使用高度聚焦的30 keV电子束激发局域表面等离子体，使其与纳米谐振器的集体共振模式耦合。我们展示了等离子体模式激发前所未有的分辨率，并通过将这些观察结果与全场模拟相结合，发现等离子体纳米结构中的阴极发光在对应于模式电场强度波腹的位置最有效地被激发。
