SEOUL – In a breakthrough that promises to reshape the global optical industry, South Korean researchers have developed a world-first technology to mass-produce "metalenses" at lightning speed. These lenses, which are hundreds of times thinner than conventional glass lenses yet capable of controlling light with unprecedented precision, can now be printed at a rate of over 300 units per second—much like a newspaper rolling off a high-speed press.

The Ministry of Science and ICT announced on the 15th that a joint research team led by Professors Cho Kyu-jin and Kim In-ki from Sungkyunkwan University (SKKU), along with Professor Rho Junsuk from POSTECH, has successfully implemented a "Roll-to-Roll (R2R) Nanoimprint" process for visible-light metalenses.

Breaking the Scalability Barrier

Metalenses are next-generation optical elements composed of nanostructures that can manipulate the phase, amplitude, and polarization of light at the nanometer scale. Despite their potential to replace bulky refractive lenses with flat, ultra-thin profiles, their commercialization has been hindered by reliance on costly and complex semiconductor fabrication processes, confining them largely to laboratory settings.

To overcome this, the research team utilized the R2R printing foundry technology developed at SKKU’s Leading Research Center. While previous methods relied on rigid nickel molds for individual production, the team engineered a flexible polymer replica mold mounted on a 12-inch cylindrical roller. This allows for continuous, seamless printing of nanostructures as the roller rotates.

High Performance Meets High Speed

The innovation isn't just about speed; it’s about reliability. The team introduced a specialized surface treatment to maximize the durability and resolution of the polymer mold. This ensures that even in a continuous 200-meter production run, the performance of the first lens is identical to the last. This system is roughly 100 times faster than existing methods.

Furthermore, by applying a high-refractive index titanium dioxide (TiO2) coating via Atomic Layer Deposition (ALD) onto the printed nanostructures, the team achieved an optical efficiency of over 90% in the visible light spectrum. Experimental results showed that the lenses could form precise focal points at the diffraction limit, achieving a Strehl ratio (a measure of lens quality) of over 0.8—a benchmark for high-performance optics.

A New Horizon for Tech Industries

The implications of this technology are vast. By reducing lens thickness by hundreds of times while maintaining high performance, it offers a fundamental solution to the "camera bump" (protruding cameras) on modern smartphones. Beyond consumer electronics, it is expected to drive innovation in lightweight Augmented Reality (AR) glasses, ultra-precision medical imaging devices, and advanced space optical systems.

"This achievement represents a total package of technological prowess, ranging from device design to high-speed mass manufacturing," the research team stated. "It will serve as the cornerstone for the commercialization of the next-generation optical industry and accelerate the realization of the R2R printing foundry platform."