Scientists: Latest cloak of invisibility may disguise light itself. Three-dimensional plasmonic cloak hides a cylinder from microwaves. New Journal of Physics - Experimental verification of three-dimensional plasmonic cloaking in free-space (14 pages) They optimized the cloak design for the 3 GHz range.
They have hidden a cylinder from microwaves, demonstrating cloaking of an object in free space, rather than a two-dimensional image. The group has not been able to scatter visible light, but it expects that cloaking small objects is possible. The results pave the way to realistic, practical applications of 3D stand-alone cloaks for radar evasion and non-invasive radio frequency probing. BBC News - The approach used is unlikely to work at the visible light part of the spectrum. Prof Alu explained that the approach could be applied to the tips of scanning microscopes - the most high-resolution microscopes science has - to yield an improved view of even smaller wavelengths of light. We report the experimental verification of metamaterial cloaking for a 3D object in free space.
'Cloaking' a 3-D object from all angles demonstrated. 26 January 2012Last updated at 03:25 By Jason Palmer Science and technology reporter, BBC News Microwaves can be seen being blocked and scattered without (l), and "reconstructed" (r) with the cloak Researchers have "cloaked" a three-dimensional object, making it invisible from all angles, for the first time.
However, the demonstration works only for waves in the microwave region of the electromagnetic spectrum. It uses a shell of what are known as plasmonic materials; they present a "photo negative" of the object being cloaked, effectively cancelling it out. The idea, outlined in New Journal of Physics, could find first application in high-resolution microscopes.
Most of the high-profile invisibility cloaking efforts have focused on the engineering of "metamaterials" - modifying materials to have properties that cannot be found in nature. Negative effects Continue reading the main story “Start Quote End QuoteAndrea AluUniversity of Texas at Austin "There is still a lot of work to do," he said. Viewcontent.cgi?article=1499&context=ese_papers&sei-redir=1&referer=http%3A%2F%2Fwww.google.co.uk%2Furl%3Fsa%3Dt%26rct%3Dj%26q%3Dplasmonic%2520cloaking%26source%3Dweb%26cd%3D3%26ved%3D0CEEQFjAC%26url%3Dhttp%253A%252F%252Frepository.upenn.edu%252Fcgi%252Fv. Metamaterials: Photonic Sleight of Hand (Photonics Spectra. Marie Freebody, Contributing Editor, marie.freebody@photonics.com Invisibility cloaks, perfect imaging, enhanced photovoltaic light collection, all-optical memories and biosensing are just some of the intriguing applications of metamaterials currently grabbing headlines in scientific journals.
The field of metamaterials is barely 10 years old. First conceived in 2000 by Sir John Pendry at Imperial College London, metamaterials relied in the early days on advances in nanotechnology to build tiny structures such as metallic rings or wires smaller than the wavelength of light. These nanostructures modify the electromagnetic properties of the metamaterial, sometimes creating seemingly impossible optical effects. Much success has already been demonstrated at microwave frequencies: metamaterial antennas, transmission lines and resonators, which have been harnessed for wireless technology applications.
Rays enter the cloak through the outer surface and are guided around the hidden region. 1367-2630_14_1_013054.