![]() Landy explained the "reflections" noted in earlier cloaks tended to occur along the edges and corners of the spaces within and around the meta-material. The cloak was naturally divided into four quadrants. In the case of earlier cloaking experiments, a small percentage of the energy in the waves was absorbed, but not enough to affect the overall functioning of the cloak. When any type of wave, like light, strikes a surface, it can be either reflected or absorbed, or a combination of both. The strips of the device, which is about two-feet square, form a diamond-shape, with the center left empty. Landy's cloak used a similar row-by-row design, but added copper strips to create a more complicated - and better performing - material. The original cloak consisted of parallel and intersecting strips of fiberglass etched with copper. Landy has now reduced the occurrence of reflections by using a different fabrication strategy. "Since the goal was to demonstrate the basic principles of cloaking, we didn't worry about these reflections." The viewer can see through the glass just fine, but at the same time the viewer is aware the glass is present due to light reflected from the surface of the glass. He explained that it was much like reflections seen on clear glass. "One issue, which we were fully aware of, was loss of the waves due to reflections at the boundaries of the device," Landy said. Smith, William Bevan Professor of electrical and computer engineering at Duke's Pratt School of Engineering. "In order to create the first cloaks, many approximations had to be made in order to fabricate the intricate meta-materials used in the device," said Nathan Landy, a graduate student working in the laboratory of senior investigator David R. Structures incorporating meta-materials can be designed to guide electromagnetic waves around an object, only to have them emerge on the other side as if they had passed through an empty volume of space, thereby cloaking the object. The Duke team has extensive experience in creating "meta-materials," man-made objects that have properties often absent in natural ones. The results of the Duke experiments were published online Nov. Just as traditional wires gave way to fiber optics, the new meta-material could revolutionize the transmission of light and waves.īecause the goal of this type of research involves taming light, a new field of transformational optics has emerged. These new findings could be important in transforming how light or other waves can be controlled or transmitted. Now a member of that laboratory has developed a new design that ties up one of the major loose ends from the original device. The first functional "cloaking" device reported by Duke University electrical engineers in 2006 worked like a charm, but it wasn't perfect. ![]()
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