Fisheye lenses have been around for a long time and are used to capture panoramic views in a single shot. These ultra-wide-angle lenses are made from multiple pieces of curved glass that can distort light to produce the wide images. The challenge with traditional fisheye lenses is that the spherical design and multiple pieces of glass makes them bulky and expensive to produce.
Engineers from MIT and the University of Massachusetts at Lowell have designed a new wide-angle lens that is completely flat and is the first flat fisheye lens to produce 180-degree panoramic images that are crisp. The “metalens” is a wafer-thin material with microscopic features working in unison to bend light in a certain way. The fisheye lens is a single flat millimeter-thin piece of glass covered on one side with tiny structures allowing for the precision scattering of incoming light.
The way the incoming light is scattered allows the lens to produce panoramic images just as a traditional curved fisheye lens would. The lens MIT and its partner have developed works in the infrared part of the spectrum, but researchers believe they could build a similar lens to work in visible light.
The team also believes the design could be adapted for various applications, such as building thin ultra-wide-angle lenses directly into smartphones and laptops. The lenses are also low-profile enough to be integrated into medical imaging devices like endoscopes and wearable electronics, virtual reality headsets, and other computer vision devices.
Researchers point out that the metalens is mostly an experimental stage at this time, but it can significantly change the field of optics. The lens design the team has come up with is a simple design, not requiring additional components. Research on the new lens was funded in part by DARPA under the EXTREME program.