Australian engineers are working on new technology that could give night vision abilities to normal glasses. 

Researchers at the ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS) have created an infrared filter that is thinner than a piece of cling wrap. 

This development could eventually lead to the integration of night vision into everyday eyewear, allowing users to simultaneously view the infrared and visible light spectra.

The miniaturisation of night vision technology has the potential to significantly expand its applications. 

Traditional night vision devices are often bulky and heavy, limiting their use to the military, hunting enthusiasts, and photographers. 

These devices typically require the user to carry around substantial equipment, making them impractical for everyday use. 

The new lightweight filters, weighing less than a gram, can be applied as a film on regular glasses. 

This innovation could make night vision accessible for activities such as driving at night, nighttime running, and working in low-light conditions.

In a study published in Advanced Materials, TMOS researchers from the Australian National University demonstrated their enhanced infrared vision non-linear upconversion technology using a non-local lithium niobate metasurface. 

Traditional night vision systems require a multi-step process involving lenses, photocathodes, microchannel plates, and phosphor screens, often needing cryogenic cooling to prevent thermal noise.

These systems are not only heavy and bulky but also typically block visible light.

The new metasurface-based technology simplifies this process, requiring fewer components and operating at room temperature, thus eliminating the need for cooling systems. 

Photons pass through a single resonant metasurface where they are mixed with a pump beam. This metasurface enhances the photons' energy, drawing them into the visible light spectrum without converting them into electrons. 

The approach allows for the capture of both visible and non-visible light in a single image, unlike traditional systems that produce side-by-side images from each spectrum.

The researchers' previous technology used a gallium arsenide metasurface, but their latest advancement employs lithium niobate, which is fully transparent in the visible range and more efficient. The new metasurface also spreads the photon beam over a wider surface area, reducing angular loss of data.

“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,” says researcher Rocio Camacho Morales.

“We choose these wavelengths because 1550 nm, an infrared light, is commonly used for telecommunications, and 550 nm is visible light to which human eyes are highly sensitive. 

“Future research will include expanding the range of wavelengths the device is sensitive to, aiming to obtain broadband IR imaging, as well as exploring image processing, including edge detection.”

More details are accessible here.