Chinese scientists have created a night vision device with full-color imaging instead of green

Researchers at Beijing Institute of Technology have built a prototype that turns infrared light into full-color images. This approach to night vision goes beyond the usual monochrome displays.

The system relies on mercury telluride quantum dots paired with a two-layer OLED display.

Instead of converting infrared radiation into a single color based on brightness, the device maps different wavelengths and intensities to distinct visible colors. That distinction turns out to matter quite a bit.

Standard infrared imaging systems rely on detectors that capture a wide range of wavelengths but don't preserve details about them. As a result, the image usually comes through as brightness variations in a single color, most often green. The method works fine, but it ignores the human eye's ability to distinguish between color shades.

The new design tackles that problem at the material level. The quantum dots in the device measure just a few nanometers across, which gives them discrete energy states. That lets them respond differently depending on the wavelength and intensity of incoming infrared light.

Longer, lower-energy wavelengths generate fewer charge carriers. Shorter wavelengths and stronger signals trigger more complex electronic transitions and produce more carriers.

These signals then feed into a two-layer OLED structure. One layer emits red light, the other emits blue. An energy barrier between the two layers controls how charge moves through the device.

With a weak infrared signal, the system outputs a dim red glow. As the signal grows stronger or shifts toward shorter wavelengths, more charge crosses the barrier and activates the blue layer, producing a color mix along with higher brightness.

Because the color output ties directly to the physics of the incoming signal rather than a preset mapping, the system carries more information. The researchers estimate it can pick up on far smaller differences in infrared power than conventional brightness-based systems.

To test the concept, the team built a lightweight prototype shaped like a pair of glasses. The gadget weighs 23 grams and is semi-transparent, letting the wearer see regular and infrared imagery at the same time. In controlled experiments, it produced clear color-coded images of simple patterns and moving objects lit by shortwave infrared light.

The system can also switch between different modes. It can overlay infrared information on top of normal vision or filter out visible light entirely for a more immersive view.

The researchers also checked whether the converted signal could be picked up by biological systems. In lab tests, infrared light processed by the device triggered a response in engineered cells that are sensitive to visible light.

Further experiments showed measurable brain activity in mice and a retinal response in human volunteers viewing infrared signals through the system. Infrared light on its own produced no such effects.

In the paper, the team states that the work "redefined infrared vision" by "moving beyond the monochromatic paradigm," and that it opens a path toward "next-generation visual prosthetics."

Limitations remain. The tests were run in controlled settings using simple, high-contrast objects, so it's unclear how the system would perform in messier real-world scenarios. The OLED component also needs external power, which makes the current version more of a wearable display than a passive optical device.

Questions about the materials remain open too. Mercury telluride is a heavy-metal compound, and the study doesn't address long-term safety or whether the approach could work in devices that contact the body directly.

For now, the work points to a different way of processing infrared imagery, one where color gets built into the perception process itself rather than tacked on afterward.