New generation of lenses to improve radar, telecom

Washington: Scientists have invented a new generation of lenses which can radically improve the capabilities of telecom or radar systems, providing greater perspective and detail.

A team of engineers, which included Nathan Kundtz, post-doctoral associate in electrical and computer engineering at Duke's Pratt School of Engineering, studied altering the material between the surfaces of the lens, instead of using the exterior to control rays.

According to the findings which appeared online in Nature Material, the new lens looks more like a miniature set of tan Venetian blinds, rather than traditional ones made of clear substances like glass or plastic, with highly polished surfaces, a Duke release said.

Yet its ability to focus the direction of electromagnetic rays passing through it dramatically surpasses that of a conventional lens, the engineers say.

The older versions of lenses have certain limitations based on what happens to the efficiently focused rays as they pass through the volume of the lens, said Kundtz.

"If you can control the volume, or bulk, of the lens, you gain much more freedom and control to design a lens to meet specific needs," he said about the new lens.

His experiments were conducted in the lab of senior researcher David R. Smith, a computer engineering professor, demonstrating for the first time what was thought to be theoretically possible.

The latest advance was made possible by the ability to fabricate exotic composite materials known as metamaterials. The precise arrangement of more than 1,000 individual pieces of the same fibreglass material of circuit boards in parallel rows directs the rays as they pass through.

The new lens has a wide angle of view, almost 180 degrees, and because its focal point is flat, it can be used with standard imaging technologies.

The researchers say a single metamaterial lens could replace traditional optical systems requiring vast arrays of lenses and provide clearer images.
Source: IANS