Technology.am (July 18, 2009) — Scientists have created a universal mirror, an object that reflects all light waves back at their source. It would have many uses including military applications, radar tracking such as installed on aircraft, boats or satellites, this mirror would make these objects easier to track with radar.
Unlike an ordinary mirror, which only reflects objects at 90 degrees, a universal mirror reflects objects back at any angle. In other words, a person positioned in front of a large, optical universal mirror would see his or her own reflection perfectly no matter where the person stands.
If a tennis player hitting a ball against a wall, the ball would bounce right back to the player no matter what angle he or she directed the shot.
These mirrors use technology called metamaterials to manipulate light waves. Metamaterials are artificial materials that derive their properties from their physical structures, unlike normal materials that are determined by their chemical composition.
The metamaterial could act like a aggressive shield, protecting objects from airplane-based, high-energy laser systems, which are being developed by Boeing, by bouncing the lasers beam back at their source.
The universal mirror or omnidirectional retroreflector is about one centimeter high, 10 centimeters in diameter, and made of copper circuit boards covered in circles three millimeters (0.1 inches) across.
When microwaves three centimeters long hit the small circles, they are forced backward at the same angle from which they came.
When microwaves hit most other materials, they bounce forward at the same angle.
When radio waves ordinarily hit these objects, they scatter in many different directions, and only a few radio waves bounce back to the original source of the radar. With a radio universal mirror, all the radio waves would bounce back to their original source, making them much easier to detect and giving the object a much larger radio profile.