Directional Control of Light-Emitting-Diode Emission Via a Subwavelength-Apertured Metal Surface

A thin Au film with a hexagonal array of subwavelength apertures has been integrated onto a semiconductor light-emitting diode. This produces a highly directional far-field pattern with a strong polarization dependence and alters the spectral shape of the light emission from the semiconductor. A two-dimensional k-space analysis of the experimental data shows good agreement with a simple model of surface plasmon to photon coupling via the periodic structure of the metal film