Letter abstract
Nature Photonics 2, 295 - 298 (2008)
Published online: 13 April 2008 | doi:10.1038/nphoton.2008.52
Subject Categories: Novel materials and engineered structures | Terahertz optics
Experimental demonstration of frequency-agile terahertz metamaterials
Hou-Tong Chen1, John F. O'Hara1, Abul K. Azad1, Antoinette J. Taylor1, Richard D. Averitt2, David B. Shrekenhamer3 & Willie J. Padilla3
Abstract
Metamaterials exhibit numerous novel effects1, 2, 3, 4, 5 and operate over a large portion of the electromagnetic spectrum6, 7, 8, 9, 10. Metamaterial devices based on these effects include gradient-index lenses11, 12, modulators for terahertz radiation13, 14, 15 and compact waveguides16. The resonant nature of metamaterials results in frequency dispersion and narrow bandwidth operation where the centre frequency is fixed by the geometry and dimensions of the elements comprising the metamaterial composite. The creation of frequency-agile metamaterials would extend the spectral range over which devices function and, further, enable the manufacture of new devices such as dynamically tunable notch filters. Here, we demonstrate such frequency-agile metamaterials operating in the far-infrared by incorporating semiconductors in critical regions of metallic split-ring resonators. For this first-generation device, external optical control results in tuning of the metamaterial resonance frequency by 
20%
. Our approach is integrable with current semiconductor technologies and can be implemented in other regions of the electromagnetic spectrum.
- Center for Integrated Nanotechnologies, Materials Physics & Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA
- Department of Physics, Boston College, 140 Commonwealth Avenue, Chestnut Hill, Massachusetts 02467, USA
Correspondence to: Hou-Tong Chen1 e-mail: chenht@lanl.gov