Meta 2006 highlights optical metamaterials
THE BAHAMAS-Photonic Metamaterials: from Random to Periodic (Meta; June 5-8, 2006, Grand Bahama Island), a new topical meeting held by the Optical Society of America (Washington, DC), brought together leading researchers in three areas of science and technology: photonics of random media, with its deep and challenging physics; photonic crystals, which has matured rapidly with the creation of intricate structures; and metamaterials, whose rapid growth has been spurred by dreams of superseding lon
THE BAHAMAS-Photonic Metamaterials: from Random to Periodic (Meta; June 5-8, 2006, Grand Bahama Island), a new topical meeting held by the Optical Society of America (Washington, DC), brought together leading researchers in three areas of science and technology: photonics of random media, with its deep and challenging physics; photonic crystals, which has matured rapidly with the creation of intricate structures; and metamaterials, whose rapid growth has been spurred by dreams of superseding long-accepted limits of optical resolution and detectability.
Designed metamaterials have developed at breakneck speed due to improved nanofabrication capabilities and the development of subwavelength-scanning imaging techniques and have opened the way for a plethora of photonic possibilities unattainable in naturally existing materials. The structural units of metamaterials can be tailored in shape and size; the composition and morphology can be artificially tuned, and inclusions with desired functionality can be precisely placed.
Although the field of metamaterials includes a large range of engineered materials with designed optical properties, the term was originally coined in connection with negative-index materials (NIMs), also referred to as left-handed materials. Such metamaterials promise to create entirely new modalities for manipulating light with revolutionary impact on present-day optical technologies. Recent experimental breakthroughs in bringing NIMs to the optical regime were described in talks by Stefan Linden (Max Plank Institute; Karslruhe, Germany) and one of the authors (Vlad Shalaev), whereas Xiang Zhang (UC Berkeley; Berkeley, CA) and Richard Blaikie (University of Canterbury; Christchurch, New Zealand) outlined progress in developing the superlens and its applications for nanoscale photolithography.
New perspectives were given on the photonics of random media and, particularly, on the so-called Anderson transition (a switchover from propagating, wavelike behavior to spatially localized photons that are trapped by multiple scattering). There were three reports of the transverse localization of light traveling in samples that are uniform in the direction of the incident beam but disordered in the perpendicular plane, a circumstance which had been proposed by De Raedt, Lagendijk and de Vries. Photon localization and the impact of nonlinearity was studied in parallel clusters of optical fibers (Thomas Pertsch et al., Friedrich-Schiller University/Institute for Physical High Technology; Jena, Germany), in a photorefractive crystal that had been exposed to a random 2-D speckle pattern interfering with stronger writing beams (Tal Schwartz et al., Technion; Haifa, Israel), and in a linear array of parallel optical waveguides (Yoav Lahini et al., Weizmann Institute of Science; Rehovot, Israel).
The impact of localization in the time domain was shown in the increasing suppression of transmission with delay from an exciting pulse for localized microwave radiation (Andrey Chabanov et al., University of Texas at San Antonio/Queens College) and optical radiation in the critical regime in a sample with ratio of mean free path to wavelength of 4p (Christof Aegerter et al., University of Konstanz; Konstanz, Germany). The creation of spatially extended states when modes spectrally overlap, termed necklace states by John Pendry, was reported in measurements of pulsed optical transmission through random porous-silicon layers (Jacopo Bertolotti, European Laboratory for Nonlinear Spectroscopy; Florence, Italy), and in microwave measurements of the field within random waveguides (Patrick Sebbah, CNRS/Queens College). These states account for the bulk of transmission in 1-D systems. -Vladimir Shalaev and Azriel Genack, cochairs, Metamaterials 2006