Resonant Optical Antennas

• Published in: Science (American Association for the Advancement of Science) Vol. 308; no. 5728; pp. 1607 - 1609
• Main Authors: Mühlschlegel, P., H. -J. Eisler, Martin, O. J. F., Hecht, B., Pohl, D. W.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 10.06.2005; The American Association for the Advancement of Science
• Subjects: Antenna design; Antennas; Computer Simulation; Conductors (Materials); Electron microscopy; Exact sciences and technology; Fiber optics; Fundamental areas of phenomenology (including applications); Information processing; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Interference (Light); Laboratory Equipment; Larvae; Laser power; Lasers; Light; Literary Devices; Micro- and nanooptical devices; Nanotechnology; Nonlinearity; Optical character readers; Optical interference; Optical resonance; Optics; Organic foods; Physics; Scanning probe microscopes, components and techniques; Stripes; Wavelengths; Manufacturing processes; Dipole antennas; Nanooptics; Field enhancement; Optical antenna; Nanotechnology; Near field optics
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1111886

We have fabricated nanometer-scale gold dipole antennas designed to be resonant at optical frequencies. On resonance, strong field enhancement in the antenna feed gap leads to white-light supercontinuum generation. The antenna length at resonance is considerably shorter than one-half the wavelength of the incident light. This is in contradiction to classical antenna theory but in qualitative accordance with computer simulations that take into account the finite metallic conductivity at optical frequencies. Because optical antennas link propagating radiation and confined/enhanced optical fields, they should find applications in optical characterization, manipulation of nanostructures, and optical information processing.