A team of researchers from China has developed a new laser device that can read millimeter-scale text from a distance of over a mile away. The device uses an advanced imaging technique called intensity interferometry, which enables super-resolution imaging of targets as small as 1.5 mm at a range of 0.85 miles.
The device consists of multiple laser emitters that work together to create high-quality images of objects in the environment. According to the study published in Physical Review Letters, the device successfully imaged letter-shaped targets measuring 8×9 mm with a resolution of 3 mm, which is 14 times higher than the diffraction limit of a single telescope.
The researchers used this technology to test the super-resolution capabilities of their device by crafting letters out of hollowed-out aluminum sheets and covering them in retroreflective materials. The letters were then placed over a kilometer away from the imaging system, where they were successfully imaged using the active intensity interferometer setup developed by the team.
The potential applications of this technology are vast, including long-range remote sensing, surveillance, and non-invasive imaging in challenging environments. With its ability to cut through atmospheric turbulence and ignore flaws in telescope optics, intensity interferometry stands out as an ideal technique for high-resolution imaging.
However, the study highlights several challenges associated with applying intensity interferometry to real-world applications, such as the lack of suitable thermal light sources and robust image reconstruction algorithms. To overcome these issues, the researchers developed a pseudothermal illumination setup using multiple laser emitters, which produced thermal illumination and reconstructed sparse, noisy data into high-resolution images.
The development of this device has significant implications for various fields, including astronomy, geology, and engineering. While more research is needed to fully realize its potential, the current results demonstrate the promise of intensity interferometry for high-resolution imaging in challenging environments.
Source: https://phys.org/news/2025-05-high-resolution-laser-device-millimeter.html