Breakthrough in night-vision technology: thin film that covers consumer glasses

Researchers have developed a night-vision technology thinner than a piece of cling wrap that could be placed on everyday eyewear. It allows users to see in both the visible and infrared spectrum at the same time.

Researchers at the Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems (TMOS) believe they have come up with something that could result in safer driving or walking in the dark and less hassle working in low-light conditions.

Currently, night vision tech requires bulky and uncomfortable headsets or uncomfortable headlamps.

TMOS researchers have now introduced an “enhanced infrared vision non-linear upconversion technology using a non-local lithium niobate metasurface.” Or, in simpler terms, an infrared filter that “is thinner than a piece of cling wrap.”

Traditional night vision technology is based on a photocathode that transforms photons into electrons, which then go through a microchannel plate to increase the number of electrons generated, and then these electrons travel through a phosphor screen to be reconverted back to photons. That produces an intensified visible image that can be seen by the eye, but the components require cryogenic cooling, the systems are heavy and bulky and often block the visible light.

Instead, TMOS researchers used metasurface-based upconversion technology, which requires fewer elements and provides an easier pathway for light photons to be processed.

“Photons pass through a single resonant metasurface where they are mixed with a pump beam. The resonant metasurface enhances the energy of the photons, drawing them into the visible light spectrum – no conversion of electrons is needed. It also works at room temperature, eliminating the need for bulky and heavy cooling systems,” the TMOS press release reads.

To deliver clearer and better-quality night vision, all that’s needed is a thin film for photon manipulation, which can be applied over traditional lenses. The work is an improvement on the researchers’ original technology, which featured a gallium arsenide metasurface.

“This is the first demonstration of high-resolution up-conversion imaging from 1550-nm infrared to visible 550-nm light in a non-local metasurface,” said author Rocio Camacho Morales.

“We choose these wavelengths because 1,550 nm, an infrared light, is commonly used for telecommunications, and 550 nm is visible light to which human eyes are highly sensitive.”

In the future, researchers expect to include an expanded range of wavelengths.

“These results promise significant opportunities for the surveillance, autonomous navigation, and biological imaging industries, amongst others,” said chief investigator Dragomir Neshev.