In a standard camera lens, light is focused onto a single point in order to magnify a scene. In telescopes, on the other hand, lenses work differently, by reflecting light back and forth to achieve greater magnification. This idea can also be thought of as "folding" light.

Researchers Eric Tremblay and Joseph Ford at the University of California San Diego are currently working on adopting the light-folding concept from telescopes to cell phone cameras and other applications. The biggest advantage of folding light is that it allows the development of super-thin lenses that provide unprecedented levels of magnification and resolution in small spaces.

Creating these lenses requires modern fabrication techniques where a diamond-tipped lathe is used to cut lenses. A computer guides the lathe to slice very specific dimensions as determined by a CAD model, so that a light beam traveling through the device reflects across the optical components at the correct angles.

The research is funded by DARPA, with initial military applications in mind, such as tracking and identifying military targets. For commercial applications, such as cell phone cameras, the technology has already received attention from Samsung and Motorola. The UCSD researchers hope that in a little more than a year, the lenses will be small enough for a cell phone - about 10 millimeters in diameter.

via: Popular Science