Every photographer worth their salt knows that the lens is just as important as the camera. Part of that is because one lens can produce a dramatically different picture then another—like the difference between a telephoto lens and a wide-angle lens. But optical clarity is also important, and the glass of a lens needs to be manufactured to very tight tolerances in order to avoid distortion in pictures. That is just as true for smartphones as it is for professional DSLR cameras, which results in the lens bump on the back of your phone. But this new lens developed by researchers from the University of Utah is just microns thick thanks to a completely new fabrication technique.
The thin, lightweight lens could produce slimmer camera phones, longer-flying drones. (📷: Dan Hixson / University of Utah College of Engineering)
The purpose of every camera lens is to bend light in a way that is beneficial for the picture. A telephoto lens, for example, needs to magnify a distant area and then focus the light through the aperture and onto the film or digital sensor. Lenses are designed to focus all of the available light, which means they need to be convex with a smooth curve. That dome shape ultimately makes the lens thick, and results in the bump on your smartphone. This new lens design completely disregards that convention in favor of a multitude of tiny microstructures that each refract light independently of their neighbors.
This lens is a flat disc that measures just a few microns thick—compared to a few millimeters thick for a conventional smartphone camera lens. It also weighs far less. The disc is made up of thousands of individual microstructures, each oriented at the proper angle to refract light towards the camera’s digital sensor. The microstructure at the very center of the lens is parallel to the sensor, while the microstructures near the edge are oriented at a relatively extreme angle.
That would result in significant distortion if there were just a few dozen microstructures, but that effect is reduced as more microstructures are added. If the number of microstructures is higher than the number of pixels the digital sensor is capable of picking up, then there wouldn’t be any distortion—at least theoretically. The researcher team developed an algorithm to determine how the microstructures should be oriented, and they say that this lens could be cheaper to manufacture than a conventional glass lens, because it can be made out of plastic.