Federico Capasso, a professor of applied physics and electrical engineering, and his team used a beam of electrons to carve a structure from titanium dioxide. Called nanofins, the structure is a set of blocks 600 nanometers tall – New Scientist describes them as the world’s smallest Stonehenge. These tiny blocks, when rotated at different angles, pull light together the same way that the traditional piece of curved glass does.
In testing, the material, mounted on a non-focusing piece of glass for stability, was sharper than a 55-millimeter microscope lens. At just 600 nanometers thick, the new lens material is 100,000 times lighter than a comparable lens from Nikon, the team said.
While the lens isn’t the first designed from metamaterials, earlier attempts lost more light in the process.
Traditional lenses use a piece of curved glass to focus the light, but to reduce distortions or cover a longer zoom range, multiple layers of glass are used, creating hefty telephoto lenses and giant telescopes. The metamaterial lens is flat, reducing much of the distortion and eliminating the need for so many layers.
The lens technology was initially only applied to red, green, and violet light, but Harvard announced earlier this week that the team has successfully developed the lens for use on the visible spectrum. While any actual lenses developed from the material are likely well into the future, the potential for dramatically reducing the size of a lens has a wide range of applications, from photography and virtual reality to microscopes.
“This technology is potentially revolutionary because it works in the visible spectrum, which means it has the capacity to replace lenses in all kinds of devices, from microscopes to cameras, to displays and cell phones,” Capasso said. “In the near future, metalenses will be manufactured on a large scale at a small fraction of the cost of conventional lenses, using the foundries that mass produce microprocessors and memory chips.”