2008/03/13 by Ashwin K. Iyer, George V. Eleftheriades, G. V. Eleftheriades · 87 citations
Engineering · Materials Science · Physics and Astronomy · #Advanced Antenna and Metasurface Technologies #Antenna Design and Analysis #Diffraction #Lens (geology) #Metamaterial #Metamaterials and Metasurfaces Applications #Negative refraction #Optics #Physics #Superlens #physics.optics
paper · pdf · doi:10.1109/tap.2009.2019890
published in IEEE Transactions on Antennas and Propagation 57(6), 1720-1727 (IEEE Antennas & Propagation Society) · 19 pages, 7 figures, submitted to IEEE Transactions on Antennas and Propagation
arxiv created 2008/03/13 · openalex publication_date 2009/06/01 · arxiv updated 2013/03/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Focusing using conventional lenses relies on the collection and interference of propagating waves, but discounts the evanescent waves that decay rapidly from the source. Since these evanescent waves contain the finest spatial details of the source, the image suffers a loss of resolution and is referred to as ldquodiffraction-limited.rdquo Superlensing is the ability to create an image with fine features beyond the diffraction limit, and can be achieved with a ldquoVeselago-Pendryrdquo lens made from a metamaterial. Such a Veselago-Pendry superlens for imaging in free space must be stringently designed to restore both propagating and evanescent waves, but meeting these design conditions (isotropicn= epsivr= mur= -1) has proven difficult and has made its realization elusive. We demonstrate free-space imaging with a resolution over three times better than the diffraction limit at microwave frequencies using a Veselago-Pendry metamaterial superlens based on the negative-refractive-index transmission-line (NRI-TL) approach, which affords precise control over its properties and is also less susceptible to losses than other approaches. A microwave superlens can be particularly useful for illumination and discrimination of closely spaced buried objects over practical distances by way of back-scattering, e.g., in tumour or landmine detection, or for targeted irradiation over electrically small regions in tomography/hyperthermia applications.