U.S. engineers developed lens system, paving way for cheaper, lighter cameras

U.S. engineers have developed a system of flat optical lenses that can be easily mass-produced and integrated with image sensors, according to California Institute of Technology (Caltech).

Researchers believe that the technology is paving the way for cheaper and lighter cameras in everything from cell phones to medical devices.

"The way we make lenses hasn't changed much since the time of van Leeuwenhoek. Until now," says Andrei Faraon, assistant professor of applied physics and materials science in Caltech's Division of Engineering and Applied Science, referring to Antonie van Leeuwenhoek, a Dutch scientist and lens-maker who created some of the first microscopes.

Published in a recent issue of the Nature Communications, the study addresses the technology relies on stacking two metasurfaces, which are sheets of material whose electromagnetic properties can be altered on demand.

Since light travels faster through the thinner glass at the edges of the lens than through the thicker glass at the center, a classical lens made of plastic or glass has a curved shape that bends the path of incoming light toward a single focal point.

The metasurfaces now accomplish the same task using silicon nanoposts, cylinders just 600 nanometers tall and with varying diameters in the hundreds of nanometers. For comparison, a strand of human hair is 100,000 nanometers wide.

In this case, the metasurfaces are dotted with tens of millions of these silicon cylinders that alter the way light passes through them.

Next, the team plans to integrate these lenses into miniaturized cameras and microscopes, and extend their functionality and operation bandwidth. Endit