Scientists in China have built a device capable of reading letters only millimeters wide from over a kilometer away. The laser, which could very well become an active spy tool, has achieved this impressive feat in real-world urban conditions.
The laser was developed by a team of researchers at the University of Science and Technology of China and described in a study published in Physical Review Letters. Using a method called active intensity interferometry, the team created a way to bypass common limits in optics and atmospheric interference.
Unlike standard imaging, which relies on collecting clear light waves through perfect lenses, laser imaging takes a very different approach. It uses several laser emitters to create what’s called pseudothermal illumination. These laser beams are sent toward the spy’s target, and two telescopes record their reflected intensity. The resulting data is run through a special algorithm that reconstructs the original image in remarkably high detail.
To put the system to the test, the researchers shaped the letters “USTC” out of aluminum sheets just 8 by 9 millimeters in size. Each letter was no more than 1.5 millimeters wide. They placed the target 1.36 kilometers away, or just under a mile.
The imaging system not only captured it but did so with a resolution 14 times higher than the theoretical limit of a single telescope. This is what makes this spy laser so powerful.
It doesn’t just zoom in on the image like other surveillance tools. It reconstructs images with super-resolution, even when the signal is weak or distorted. It is also robust against environmental challenges, which makes it suitable for outdoor use, unlike many lab-based optical systems.
While the device is still in the research stage, it has huge potential for applications like long-distance remote sensing, non-invasive imaging in hazardous environments, and high-precision surveillance.
If further developed, it could become an essential tool in areas ranging from public safety to disaster monitoring. Combine this breakthrough with the spy robot that melts after it completes its mission, and the world of espionage is getting very exciting.
