New Lens Could Change How Cameras Are Designed

There are many types of camera lenses available for professional photographers to achieve their desired level of magnification and detail, but a recent discovery could replace traditional bulky lenses with much thinner designs.

Professor Rajesh Menon showing the prototype of his super-achromatic lens. (Image courtesy of the University of Utah.)

A team of engineers has developed a new ultrathin and flat camera lens. This represents a significant departure from cameras in use today, which require several curved lenses to bend each color at a focal point.

"Instead of the lens having a curvature, it can be very flat so you get completely new design opportunities for imaging systems like the ones in your mobile phone," said Rajesh Menon. "Our results correct a widespread misconception that flat, diffractive lenses cannot be corrected for all colors simultaneously."

Creating a Flat Camera Lens

To properly focus and register an image, whether through a camera or an eye, all colors must travel through lenses and converge at a focal point: either a camera sensor or the eye’s retina. As light bends through multiple stacked curved lenses, refraction causes the colors to meet at the focal point in the same focus.

The flat lens developed by Menon’s team is 10 times thinner than the width of a human hair and hence millions of times thinner than a camera lens today. Using diffractive principles where light interacts with the lens on a microscopic scale and bends, the team developed specific algorithms to calculate the lens geometry required to enable the different colors to pass through the lens and focus at a single point.

The earliest example of an achromatic lens, an achromatic doublet, brings red and blue light to the same focus.

They’ve named it the “super-achromatic lens” and it can be made using transparent materials such as glass or plastic.

"What's new is we showed that we could actually engineer the bending of light through diffraction in such a way that the different colors all come to focus at the same point. That is what people believed could not be done,” said Menon.

A Better Camera for Your Smartphone

Since Menon and his team have proven that the lens works in the lab, they believe the first commercial applications could be seen within five years. On top of creating lightweight and efficient lenses for cameras, the lens’ applications extend to eyeglasses, thinner endoscopes in medicine, cameras used in drones, and satellites.

The research was published under the title “Chromatic-Abberation-Corrected Diffractive Lenses for Ultra-Broadband Focusing” in the journal Scientific Reports.