A domestic research team has developed an ultrathin metalens technology that can freely switch between two-dimensional (2D) and three-dimensional (3D) screens on a single display. It significantly widens the narrow viewing angle long seen as the biggest weakness of existing 3D displays, while also reducing image quality degradation in 2D mode, raising expectations for practical use.
A team led by Noh Jun-seok at Pohang University of Science and Technology POSTECH said it developed a technology that switches between 2D and 3D with a single lens by using a metalens, a next-generation optical component, in collaboration with the Visual Technology Team at Samsung Electronics Samsung Research. The findings were published in the journal Nature on the 23rd.
A metalens is a very thin, flat next-generation lens. Instead of shaping thick glass like a conventional lens, it tightly arranges structures measured in nanometers (nm, one-billionth of a meter), far smaller than a human hair, to precisely control the direction and properties of light. It is also commonly known as a material for a "transparent cloak."
Using this ultrathin structure, the researchers implemented a display lens that is much thinner than before while operating more intelligently.
The core of this technology is that a single metalens plays different roles depending on whether voltage is applied. Without voltage, it works like a concave lens to show a standard 2D screen without distortion; when voltage is applied, it acts like a convex lens, changing the direction of light to create a stereoscopic image.
According to the researchers, the technology widens the viewing angle to 100 degrees, delivering an ultrawide viewing angle more than six times broader than before. Conventional glasses-free 3D displays had an effective 3D viewing angle of around 15 degrees, meaning practically only one person could enjoy the screen. Also, because they were designed around the 3D function, image quality tended to drop when viewing 2D content.
Unlike conventional 3D lenses that are millimeters thick, the device the team implemented has an ultrathin structure of about 1.2 mm. It is therefore easy to fit into existing device architectures such as smartphones or tablets. In fact, the team inserted the metalens into a phone panel provided by Samsung Electronics to verify its operation.
Noh said, "For commercialization, we need to address issues such as repeatability in mass production, demand, higher resolution, and improved transmittance," adding, "Current metalenses do not transmit 100% of light, so the screen may appear somewhat blurry; if this is improved, brightness and sharpness can be enhanced."
Separately, Noh previously published in Nature a study on metalens mass-production process technology. By following up with results applying metalenses to an actual display, the team demonstrated both the underlying technology and the potential for mass production.
Noh explained, "In the past, making a single metalens cost about 5 million won, but recent advances in large-area production technology have reduced the unit cost to under 5,000 won," adding, "This will contribute to securing foundational display technology with broad application potential, from smartphones to industrial billboards."
References
Nature (2026), DOI: https://doi.org/10.1038/s41586-026-10318-9