Researchers in China have unveiled an innovative laser apparatus capable of deciphering characters as small as millimeters from distances exceeding a kilometer, which could transform surveillance technology. This laser, developed by scientists at the University of Science and Technology of China, is described in a paper published in *Physical Review Letters*. It utilizes active intensity interferometry to bypass conventional optical and atmospheric hurdles.
In contrast to traditional imaging methods that depend on clear light waves and ideal lenses, this laser imaging employs pseudothermal illumination. Numerous laser sources direct beams toward a target, and two telescopes collect the reflected intensity. A sophisticated algorithm then reconstructs the image with remarkable accuracy.
To evaluate the system, researchers fashioned the letters “USTC” from aluminum sheets, each measuring just 1.5 millimeters in width, and positioned them 1.36 kilometers away. The system successfully captured the image with a resolution 14 times greater than what a single telescope’s theoretical limit would allow, showcasing its capabilities.
This technology doesn’t simply magnify like other surveillance devices; it reconstructs images with super-resolution, even when dealing with weak or distorted signals. Its robustness against environmental obstacles makes it ideal for outdoor applications, unlike many systems confined to laboratories.
Although still undergoing research, this device presents significant prospects for long-distance remote sensing, non-invasive imaging in dangerous settings, and high-precision surveillance.
