“The experimental demonstration at blue, green and red light looks impressive,” says Steven Cummer, an electrical engineer at Duke University. The holey pattern in the sponge-like cloak curves ...

The spectral cloak operates by selectively transferring ... then light in the green range might be shifted to blue - so there would be no green light for it to reflect. Then, once the wave has ...

That means the cloak can work perfectly if you're only looking with red light. But in blue or yellow light, the 'hidden' object may be perfectly visible. For us humans, who use the whole visible ...

The light exiting the cloak must also match the polarization ... the material would exhibit a negative refractive index over a band from blue to red, only missing the very extremes of the visible ...

An invisibly cloak would work by 'grabbing hold' of light waves and making them flow ... Broadband invisibility clearly is blue-skies research,' said Prof Leonhardt. 'I will try my best to explore ...

That cloak worked only for light of a specific ... have been used to hide centimetre-size objects under red, green and blue light (Physical Review Letters, vol 106, p 033901).