Superthin lens can function as both zoom and wide angle

Telegraph : Unlike conventional lenses, which consist of curved glass surfaces that alter the direction of light as it passes through, a new lens is being developed that is made of an ultrathin, flat piece of glass with a layer of gold rods laid on top. A prototype has been built that has an aperture of 80 μmâmdash;about the width of a human hairâmdash;and a focal length of 60 μm. The researchers are able to switch the tiny lens from wide-angle mode to zoom mode by placing a filter in front of it, which changes the polarization of the light. Shuang Zhang at the University of Birmingham and colleagues are now working to make larger lenses that could be used in electronic devices such as cellphones. Their findings have been published in Nature Communications.