Researchers of Purdue University, West Lafayette, IN, US announced that they have created a new type of invisibility cloak which works for all colors of the visible spectrum. This new technology, based on a tapered optical waveguide, is simpler than previous designs and makes it possible to cloak objects of about 50 microns in diameter – roughly the width of a human hair. “All previous attempts at optical cloaking have involved very complicated nanofabrication of metamaterials containing many elements, which makes it very difficult to cloak large objects,” said Vladimir Shalaev, Purdue University’s Robert and Anne Burnett Professor of Electrical Engineering. “Here, we showed that if a waveguide is tapered properly it acts like a sophisticated nanostructured material.” Previous experiments with metamaterials have been limited to cloaking regions only a few times larger than the wavelengths of visible light. This findings could lead to advances in e.g. cloaking; powerful “hyperlenses” resulting in microscopes 10 times more powerful than today’s; computers and consumer electronics that use light instead of electronic signals to process information; advanced sensors; and more efficient solar collectors. Findings are detailed in a research paper appearing May, 29 in Physical Review Letters.
Researchers at Bio Nano Consulting (BNC), London, UK, have produced a miniaturized version of the London tube map, measuring only 2×3 mm. The map was etched using lasers by Dr Richard Winkle, a BNC researcher at Imperial College London, whilst testing the capabilities of a laser micromachining system. The ‘London Nanotube’ was aptly named as nanotubes are an essential building block for nanotechnology. Dr Mike Fisher, business development director of BNC commented, “This version of the London Nanotube is not strictly on the nanoscale. We believe we can shrink the tube map another 100 times, making it invisible to the naked eye.”