Value context and insight. lkm@koreatimes.co.kr
Korean researchers advance high-speed production of nano-thin lenses
From left are researchers Cho Gyou-jin, Rho Jun-suk and Kim In-ki / Courtesy of Sungkyunkwan University
By Lee Kyung-min
A joint research team from Sungkyunkwan University and Pohang University of Science and Technology (POSTECH) has developed a breakthrough manufacturing process capable of producing advanced flat “metalenses” — ultrathin lenses engineered with nanostructures — at unprecedented speed, a step that could bring the technology closer to widespread industrial use.
The researchers said Thursday that they had developed a roll-to-roll nanoimprinting process capable of producing more than 300 metalenses per second, boosting productivity by roughly 100-fold compared with existing methods.
The findings were published Thursday online in Nature, one of the world’s leading scientific journals, the team said.
The researchers said the technology overcomes a key bottleneck that has confined metalens production largely to laboratory settings, opening the door to high-speed, low-cost mass manufacturing.
Metalenses are ultrathin optical devices that use nanostructures hundreds of times thinner than human hair to control light. They can replace bulky conventional lenses but have been difficult to commercialize because of costly, semiconductor-based fabrication processes.
The team said it applied a roll-to-roll technique similar to newspaper printing, continuously forming nanostructures on flexible substrates. Using this approach, the researchers produced metalens arrays every 1.5 seconds on a 12-inch-scale process.
The researchers also said they significantly improved lens performance. By coating low-refractive-index polymer structures with a titanium dioxide thin film using atomic layer deposition, they increased light-focusing efficiency from about 10 percent to as high as 90 percent.
The team said the lenses operate across the full spectrum of visible light. In testing, they achieved near diffraction-limited focusing — essentially the physical limit of how sharply a lens can focus — producing images as crisp as the laws of physics allow.
Cho Gyou-jin, a researcher at Sungkyunkwan University, said the technology enables high-speed, low-cost production without environmental pollution and could evolve into a globally competitive manufacturing platform.
Kim In-ki, also a researcher at Sungkyunkwan University, said the integration of design, fabrication and application technologies across the three research groups had achieved a high level of completeness, adding that mass production of metalenses could accelerate their use in ultracompact cameras for robots and drones, as well as in bio and medical imaging devices.