The Harvard team used nanofabrication techniques to form the optical antenna, which consists of two gold rectangles, each 1.2 microns long, separated by a narrow gap (100 nm). Light from the laser illuminates the antenna, resulting in an intense spot of light in the gap of size seventy times smaller than the wavelength. This is far smaller than what would be possible with the conventional approach of forming a spot of light by focusing with a lens. Due to the wave nature of light, such a spot would have a diameter of more than 7 microns.
Image credit: Nanfang Yu, Ertugrul Cubukcu, and Federico Capasso, Harvard. |
