Copper-wire ‘metamirror’ reflects selectively
Only one wavelength bounces back; others pass through unimpeded
![mirror made of copper wire](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/03/ag_metamirror_free.png?fit=860%2C460&ssl=1)
PICKY MIRROR A mirror made of copper wire embedded in plastic (left) reflects microwaves with a wavelength of about 60 millimeters. Other light passes right through the mirror.
V.S. Asadchy et al/Physical Review Letters 2015