By controlling how light bends around an object, researchers have built a shrinking device that makes objects appear smaller than they actually are. Although the original object does not actually shrink, the illusion of the smaller object is convincing enough to confuse viewers since the real size of the object cannot be perceived. The team of engineers, led by Wei Xiang Jiang and Tie Jun Cui from Southeast University in Nanjing, China, has published their study on their shrinking device in a recent issue of Applied Physics Letters.
“The shrinking device can shrink the size of an object virtually, so we named it a ‘shrinking device,’” Cui told PhysOrg.com. “Such a device works at microwave frequencies and will confuse the radar or other electromagnetic detection equipment to make wrong decisions. Hence it may have potential applications in the military.”
The researchers built the shrinking device out of metamaterials, which are best known for their role in invisibility cloaks. When used in the field of transformation optics, metamaterials can bend light and control its path in desired ways.
Here, the researchers used metamaterials to build eight concentric rings that are each 12 mm high. They then placed an arbitrary object, such as a spoon, in the center of the rings. When light waves propagate through the shrinking device, the wave fronts begin to bend and their wavelengths get compressed. When the light reaches the inner circular region, the wavelengths become decompressed. To an observer on the outside of the shrinking device, the manipulated light creates the illusion of a smaller object with the same shape as the real object.