Flat Optics is a groundbreaking technique that manipulates light at the nano scale by patterning ultra -thin surfaces with nanostructures. Unlike traditional optical systems that rely on bulky lenses and mirrors, the flat optics ultra -compact, high -performing optical devices allow. This innovation is particularly crucial when it comes to miniaturizing smartphone cameras (decreases “camera bolt”) and promotes AR/VR technology.

Metasurfaces, one of the most promising applications of flat optics, rely on hundreds of millions of nanostructures to exactly try and control the phase distribution of light. In this context, sampling refers to the process of converting analog optical signals to discrete data points – similar to how the human brain processes visual information by quickly capturing multiple images per second to create continuous perception. However, traditional sampling methods have challenges. When the sampling speed is too low, aliasing artifacts occur, which leads to distorted images and optical inefficiency. A well -known example is the wagon wheel effect, where a spinning wheel in a video seems to move back or freeze due to insufficient car speeds. This aliasing issue is an important limitation in the design of metasyspace, which significantly reduces optical efficiency and precision.

For decades, researchers have relied on the Nyquist sampling kit to predict and mitigate aliasing. However, the Postech team discovered that Nyquist’s theorem, although useful for digital signal processing, does not fully account for the optical complexity of metasurfaces. While the Nyquist theory effectively defines frequency limits for digital signal processing, it fails to precisely predict or prevent optical distortion in metasurfaces, which must be responsible for both the complex nano structure of metasurfaces and the nature of the wave.

To address this limitation, the team developed a new multidimensional sampling theory that contains both the two -dimensional grid structure of metasurfaces and light wave properties. Their research revealed for the first time that the geometric relationship between a metasy surface’s nanostructured grids and its spectral profile plays a crucial role in determining optical performance. By adjusting the grid rotation and integrating diffraction elements, the team introduced an anti-aliasing strategy that minimizes noise and improves light control. Using this approach, they successfully reduced optical noise over a wide spectrum-from visible light to ultraviolet wavelength and showed metal senses with high numerical aperture (NA) and metahologram with a wide angle that works in the ultraviolet regime. This study not only redefines the theoretical framework for optical metasurfaces but also relaxing manufacturing restrictions, making high-resolution ultraviolet and high-numeric users of metasurfaces more feasible.

Professor Junsuk Rho emphasized the importance of their discovery: “This research opens up new opportunities for the next generation’s flat optical units, including high-na metal and wide-angle meta-hologram. Our newly developed sampling theory is very versatile, exciting wavelengths from microwaves to an extreme ultraviolet.

This research is supported by Posco, Samsung Electronics, the Ministry of Science and ICT and the National Research Foundation of Korea.