Beaming Light from a Subwavelength Aperture

Lezec, H. J.
Degiron, A.
Devaux, E.
Linke, R. A.
Martin-Moreno, L.
Garcia-Vidal, F. J.
Ebbesen, T. W.

¹ISIS, Louis Pasteur University, 4 rue B. Pascal, 67000 Strasbourg, France. ²NEC Research Institute, 4 Independence Way, Princeton, NJ 08540, USA. ³Departamento de Fisica de la Materia Condensada, ICMACSIC, Universidad de Zaragoza, 50015 Zaragoza, Spain. ⁴Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, 28049 Madrid, Spain.

*To whom correspondence should be addressed. E-mail: [email protected]

15 March 2002; accepted 28 May 2002

Published online 20 June 2002; 10.1126/science.1071895

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Science 297(5582):p 820-822, August 2, 2002.

Light usually diffracts in all directions when it emerges from a subwavelength aperture, which puts a lower limit on the size of features that can be used in photonics. This limitation can be overcome by creating a periodic texture on the exit side of a single aperture in a metal film. The transmitted light emerges from the aperture as a beam with a small angular divergence (approximately ±3°) whose directionality can be controlled. This finding is especially surprising, considering that the radiating region is mainly confined to an area with lateral dimensions comparable to the wavelength of the light. The device occupies no more than one cubic micrometer and, when combined with enhanced transmission, suggests that a wide range of photonic applications is possible.