Researchers Use Nanotechnology to Shrink Optics for Devices

University of Ottawa researchers have done some groundbreaking work on lenses, using nanotechnology to develop so-called metalenses that dramatically shrink down optics. But lenses still rely on space to produce images and the researchers have presented the concept of an optical “spaceplate” that propagates light for a distance much longer than the plate thickness, enabling future imaging systems to shrink even further. A spaceplate can be used to miniaturize all kinds of devices that manipulate light. “It’s a possibly revolutionary development in the field of optical science,” suggests photography and camera news site PetaPixel.

According to PetaPixel, in addition to ultra-thin cameras, the technology would benefit “solar concentrators, collimators for light sources, integrated optical components, and spectrometers.”

At the University of Ottawa, Boyd Research Group senior postdoctoral fellow Dr. Orad Reshef and Department of Physics research chair in quantum photonics and associate professor Dr. Jeff Lundeen, who lead the research team, said they want “to address how light spreads out between optical elements and tackle aspects of that process that lens elements can’t do anything about.”

Reshef said that, “light naturally spreads out when it travels, and every optical device currently used relies on that spread in order to work,” pointing to “the large gap between the eyepiece and the objective lens in a telescope or a camera lens … [which] rely on that distance and spread in order to properly function.”

That gap takes up a lot of space and the spaceplate “is able to take that same spreading of light and compress it into a ‘counterpart’ to the lens and allow whole imaging systems to get dramatically smaller as a result.”

“We considered what would happen if you manipulated light based on the angle rather than the position of a light ray,” said Lundeen. “Angle is a completely novel domain, and … we identified a useful application, compressing space. And then we showed that we could actually design and experimentally demonstrate plates that do exactly that.”

Reshef said, “this development would theoretically allow lens makers to shrink down all manner of large devices that were before thought impossible to miniaturize.” The spaceplate “could work in tandem with a metalens to significantly reduce the size of optics to the point where, in example graphics, the lens appears flush with a camera’s sensor.”

“We already have some designs to increase the compression factor from five to over 100 times, and to increase the total transmission,” said Lundeen.

In SciTechDaily, Lundeen said the idea came from a discussion with Reshef, an expert “in using nanotechnology for manipulating a ray based on its position,” about “the limitations of manipulating light with these meta-surfaces.” Lundeen suggested manipulating light based on its angle, and Reshef “was immediately confident that he could design and fabricate something that could do that.”

Both researchers came up with “viable and completely different designs, which showed there were many ways to create such a device.” Lundeen noted that the spaceplate combined with metalenses could create a flat, thin iPhone Max with “as much as 14 times better resolution and low-light performance than those large and heavy cameras.”

The full research report is available online.