Scientists in the United States have reported they are a step closer to creating invisibility-cloak technology, after masking a large, free-standing object in three dimensions. The lab work is the latest advance in a scientific frontier that uses novel materials to manipulate light, a trick that is of huge interest to the US military.
Reporting in the New Journal of Physics, researchers at the University of Texas in Austin cloaked an 18-centimetre cylindrical tube from light in the microwave part of the energy spectrum. To the human eye however, which can only perceive light in higher frequencies, the object was still visible.
According to scientists the experiment is important proof of a principle that so-called plasmonic meta-materials can achieve a cloaking effect. A warplane cloaked with such materials could achieve “super-stealth” status by becoming invisible in all directions to radar microwaves, according to co-lead investigator Assistant Professor Andrea Alu.
Plasmonic meta-materials are composites of metal and non-conductive synthetics that are made of nanometre-sized structures far smaller than the wavelength of the light that strikes them. As a result, when incoming photons hit the material, they excite currents that make the light waves scatter. Read the full article »»»»