Scientists from the University of Science and Technology of China have created a powerful laser system that can clearly read letters just 3 millimeters wide from a distance of 1.36 kilometers (almost 1 mile).
This new technology, which uses a method called active intensity interferometry, can display long-distance imaging. The study was published in the journal Physical Review Letters.
The researchers used a new way of capturing the image by focusing on how light bounces off the target. This technique measures the tiny changes in the strength of light as it returns from the object, which helps to rebuild a clear image.
The system works by using eight infrared laser beams that are aimed at the target. Then, two telescopes are used to capture the light that is reflected. By comparing the differences in the light captured by each telescope, the scientists can create a sharp image, even if the object is very far away.
“Through outdoor experiments, we have successfully imaged millimeter-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.
The method was originally used in radio astronomy to observe stars, which are very far away and not easy to study with regular telescopes. The Chinese researchers have proven that this method also works for objects on Earth, even those that do not give off their own light.
The laser system is strong enough to read letters smaller than the width of a pencil from nearly a mile away. According to the team, the technology could be used in many fields, like monitoring wildlife from a distance, checking tall buildings for damage, or even tracking space debris in orbit.
Paul McManamon, the president of Exciting Technology LLC and technical director of the University of Dayton’s Lidar and Optical Communications Institute, said the results are impressive. He explained that usually, high resolution requires a huge telescope. But with this new system, the same effect can be reached by spreading out smaller telescopes and laser beams across a wide area.
“This looks like a very interesting result. Normally, to have very high resolution you need a very large aperture due to the diffraction limit. By having multiple receive apertures [in this case telescopes] spread out across the same distance as a large single receive aperture you can have similar resolution, although some features may be missing at certain spatial frequencies. When you then also add multiple transmit apertures [laser emitter], you can further enhance the resolution,” McManamon told Newsweek.
Still, scientists say there are some challenges. For example, the system needs a clear line of sight to the target. Also, the target must be directly lit with laser beams. This means the system may not work well in secret operations or surveillance missions, where it is important to stay hidden.
The researchers plan to improve the system by making the laser beams easier to control and point at distant targets. They are also exploring the use of artificial intelligence (AI) to help build the images more accurately and quickly. Adding AI could make the system even more powerful and useful in the future.
The technology has already shown its ability to cut through problems that normally make long-distance imaging hard, like bad weather or air turbulence. Because the system looks at changes in light rather than a direct reflection, it can work better in less-than-perfect conditions.
The ability to see such small details from a great distance could be useful in many real-world situations. For example, workers could inspect large bridges or skyscrapers without needing to climb them. Scientists could also use the system to study animals in the wild without disturbing them. In space, the method might help track dangerous debris floating in Earth’s orbit.
The laser imaging system is still in its early stages, but the results so far are very promising. The research team is excited about what comes next, and they believe their work could change how we view and study distant objects.
