China develops laser telescope that can see objects as wide as a matchstick head from over a kilometre away

Chinese researchers have developed a laser system that can detect tiny text and fine details from a distance of 1.36 kilometres, a new study published in Physical Review Letters has revealed. The team from the University of Science and Technology of China tested a laser-based method that achieved a 14-fold improvement in resolution compared to traditional optical imaging using a single telescope.

New method focuses on light patterns, not image clarity

Instead of focusing directly on capturing an image, the team used a technique called active intensity interferometry. This method is based on how light interacts with a surface rather than what the object looks like. Unlike traditional telescopes that rely on self-luminous sources like stars, this system can detect non-luminous objects.

Infrared lasers and dual telescopes power the system

According to Science Alert, the system emits eight infrared laser beams across a specific point. Two telescopes capture the intensity of the reflected light. By comparing the signals from the telescopes and calibrating the laser beams, researchers were able to reconstruct an image of the target.

“Through outdoor experiments, we have successfully imaged millimetre-scale targets located at 1.36 km away, achieving a resolution enhancement by about 14 times over the diffraction limit of a single telescope,” the study authors wrote.

Letters smaller than a pencil width made visible from far away

The team reported that the system could accurately read letters at a resolution of 3 millimetres, which is smaller than the width of a standard pencil. They said this marked a significant increase in spatial resolution, well beyond what a single telescope could achieve under normal conditions.

Practical uses and current limitations

The researchers said the method has potential for high-resolution imaging and optical sensing. However, they also pointed out limitations. The system needs a direct line of sight and requires active illumination using lasers. This may not be suitable for stealth operations like covert surveillance.

Future improvements under consideration

The team plans to enhance laser control to allow easier targeting. They also aim to include artificial intelligence (AI) to help reconstruct images more accurately in the future.