Although manufacturers are constantly trying to make smartphones thinner and lighter, they're limited by the phones' curved glass camera lenses. Now, however, researchers have developed a flat lens that's one one-thousandth the thickness and one one-hundredth the weight of a conventional model.
Ordinarily, digital camera lenses work as a single cohesive unit, with the entire lens bending incoming light to focus it onto a sensor. For this reason, smartphone lenses are typically at least two millimeters thick.
Scientists at the University of Utah set out to change that, creating a prototype lens that is made up of an array of microstructures. Each one of those structures in turn serves as a sort of mini-lens, bending light to focus it onto one section of the camera's sensor. All of them thus contribute "patches" of light, to form a single image.
"You can think of these microstructures as very small pixels of a lens," says Assoc. Prof. Rajesh Menon. "They're not a lens by themselves but all working together to act as a lens."
While the image quality is similar to that of a regular lens, the Utah device measures just a few microns thick – that's one twentieth the thickness of a human hair. Additionally, whereas traditional decent-quality lenses must be made of relatively heavy and costly glass, the flat lens is made of cheaper, lighter plastic.
As an added benefit, the new lens is capable of capturing long-wave infrared light. This attribute could allow for its use in lighter, less expensive night vision systems on phones, drones, or even soldiers' goggles.
A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences. And for an earlier example of an ultra-thin lens made up of an array of mini-lenses, check out the prototype created at Harvard University.
Source: University of Utah
