Researchers from the Australian National University (ANU) have advanced night vision technology by creating an infrared filter that is “thinner than a piece of cling wrap”.
The filter could one day be placed on everyday eyewear, allowing the user to view the infrared and visible light spectrum at the same time.
Current night vision devices – which have primarily been used by the military, hunting enthusiasts, and photographers – are cumbersome. Therefore, miniaturising night vision may lead to widespread adoption.
In the study, published in Advanced Materials, the researchers demonstrated enhanced infrared vision non-linear upconversion technology using a non-local lithium niobate metasurface.
Traditional night vision technology works by converting infrared light into electrons, amplifying those electrons, and then converting them back into visible light.
This process involves several components: a lens, a photocathode, a microchannel plate, and a phosphor screen. These components require a heavy cooling system to be avoid interference from heat. Additionally, they often block visible light.
Metasurface-based upconversion technology simplifies this process. It uses a single metasurface, which interacts with a pump beam to convert infrared light directly into visible light. This method works at room temperature, eliminating the need for cooling systems to significantly reduce the device’s size and weight
The work is an improvement on the researchers’ original technology, which featured a gallium arsenide metasurface. The new metasurface is made from lithium niobate, which is fully transparent in the visible range, making it far more efficient.
More reading
COVID-19 virus shown to breach retinal barrier and damage the eye
Visual test could predict dementia onset a decade before diagnosis
Advancements in 3D printing could revolutionise IOL production
