A new type of mirror that reflects light perfectly has been constructed, a feat many scientists thought wasn’t possible. The mirror could find its way into powerful lasers and other devices.
Modern technology relies on trapping light and shuttling it around, whether to carry data over the Internet or to play a DVD. Engineers prevent light from escaping by directing it to bounce off reflective materials, but there are drawbacks to that process. Many mirrors absorb, rather than reflect, some of the light that strikes them, and the glass in fiber-optic cables works only if light grazes it at a very low angle.
Physicist Chia Wei Hsu and colleagues at MIT weren’t looking to invent a mirror when they were studying the behavior of light interacting with a photonic crystal, a slab of material with a network of drilled holes, each so small that it can manipulate individual light waves. Most of the time, light penetrated at least partially into the team’s crystal, a block of perforated silicon nitride. But when the researchers shined a specific frequency of red light at a 35-degree angle to the surface of the slab, they were surprised to find that it bounced back completely — none of it leaked away or got absorbed.
To read more, click here.