A house of mirrors can fool you into thinking a wall is really an open corridor; using metamaterials, the opposite is possible. The first practical demonstration of illusion optics shows that an open passageway can take on the appearance of a mirror wall – suggesting that in future it may be possible to emulate Alice and pass through the looking glass.
The demonstration, conducted in a two-dimensional electrical version of an optical system, relies on replicating the negative refractive index of some metamaterials. This property causes light entering or exiting the metamaterial to refract "backwards" – as if reflected off a mirror passing at a right angle through the surface of the metamaterial.
If a chunk of such a metamaterial formed one wall of a corridor, the magic would begin. Shining a light down the corridor would illuminate the walls as normal, but instead of bouncing off the metamaterial wall and continuing down the corridor, the light would be refracted at the interface and enter the metamaterial.To read the rest of the article, click here.