An invisibility cloak that works in the microwave region of the electromagnetic spectrum has been unveiled by researchers in the US. The device is the first practical version of a theoretical set-up first suggested in a paper published earlier in 2006.But Harry Potter's cloak, unfortunately, is a ways off...
The cloak works by steering microwave light around an object, making it appear to an observer as if it were not there at all. Materials that bend light in this way do not exist naturally, so have to be engineered with the necessary optical properties.
So far, the technology works only in the microwave region of the spectrum. The problem with visible light is that it has a much smaller wavelength, meaning an optical metamaterial would have to be built on the nanoscale, which is beyond the limits of current nanotechnology. It, too, would only work at a specific frequency.(Photo from 3QuarksDaily is for illustrative purposes only.)