Thaindian News

London, Dec 21 (ANI): American researchers have successfully developed a new generation of lens that could significantly enhance the capabilities of telecommunications or radar systems to give a wide field of view and improved detail.

Engineers from Duke University created the new lens, which looks like a small set of tan Venetian blinds.

The making of the lens was made possible by the ability to fabricate exotic composite materials known as metamaterials - all man-made materials that can be engineered to reveal properties not easily found in nature.

The prototype lens, measuring four inches by five inches and less than an inch high, is composed of over 1,000 individual pieces of fibreglass material and is impressed with copper. It is the specific arrangement of these pieces in parallel rows, which directs the rays when they pass through.

Nathan Kundtz, post-doctoral associate in electrical and computer engineering at Duke’s Pratt School of Engineering, said: “For hundreds of years, lens makers have ground the surfaces of a uniform material in such a way as to sculpt the rays as they pass through the surfaces.

“While these lenses can focus rays extremely efficiently, they have limitations based on what happens to the rays as they pass through the volume of the lens.”

Kundtz added: “Instead of using the surfaces of the lens to control rays, we studied altering the material between the surfaces…. 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.”

The results of his experiments, which were conducted in the laboratory of senior researcher David R. Smith, the William Bevan Professor of Electrical and Computer Engineering, appeared as an advanced online publication of the journal Nature Materials.

Since the use of traditional lenses is limited, scientists have been looking at other alternatives like the gradient index (GRIN) lenses for a long time. These are clear spheres, and better than traditional lenses but they are difficult to make and the focus point is spherical. Moreover, the spherical image is not always rendered clearly on a flat surface, as most sensing systems are oriented in two dimensions.

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

Senior researcher David R. Smith, the William Bevan Professor of Electrical and Computer Engineering, said: “We’ve come up with what is in essence GRIN on steroids.

“This first in a new class of lenses offers tantalizing possibilities and opens a whole new application for metamaterials.”

Smith added: “While these experiments were conducted in two dimensions, the design should provide a good initial step in developing a three-dimensional lens…The properties of the metamaterials we used should also make it possible to use infrared and optical frequencies.”

The findings have been published online in the journal Nature Materials. (ANI)