No matter the angle light hits, it bounces back along the same path
K. Lee et al/arXiv.org 2015
Light that strikes a new and improved mirror is always returned to sender.
South Korean physicists have created a composite mirror, made up of about a thousand tiny reflectors, that coaxes light waves to retrace, in reverse, the paths taken by the original waves that struck it. As a result, the researchers were able to reproduce an image at the same spot where it originated, even though the initial light waves had been severely scattered on their way to the mirror. This phase-conjugation mirror, reported in a paper to appear in Physical Review Letters, is not the first of its kind but requires less equipment and preparation time than its predecessors. “It’s very simple and elegant,” says Allard Mosk, a physicist at the University of Twente in Enschede, the Netherlands.
The researchers tested their device by projecting an image of the numeral 5 through