Imagine a screen so thin it’s barely visible—yet capable of displaying dozens of different high-resolution images, all hidden in the same place.
That’s exactly what researchers at POSTECH (Pohang University of Science and Technology) have achieved with a new ultra-thin display technology.
Led by Professor Junsuk Rho, the team has developed a way to fit up to 36 unique images onto a surface thinner than a human hair.
The breakthrough was recently published in the journal Advanced Science.
This impressive feat is made possible by a cutting-edge material called a metasurface. It’s a flat layer made up of tiny pillars—called meta-atoms—constructed from silicon nitride, a material that’s both tough and very good at letting light pass through.
These nano-pillars are carefully arranged so they can manipulate light with extreme precision.
What makes the technology truly remarkable is how it takes advantage of light’s properties—specifically its wavelength (or color) and polarization (the direction it spins).
Depending on the type of light you shine on the surface, you can see a completely different image. For example, red light spinning in one direction might reveal a picture of an apple, while the same red light spinning the other way might show a car.
By combining 18 different light wavelengths with two types of spin, the team created a 36-image system that can display crisp, high-quality holographic visuals. They even expanded the technology to include light beyond what we can see, reaching into the near-infrared spectrum to encode 8 more images on the same surface.
Previous attempts to create multi-image holograms often struggled with blurry results or unwanted overlapping images. The POSTECH team overcame these issues with a special noise suppression algorithm, which sharply reduces visual “crosstalk” and keeps each image clear and distinct.
According to Professor Rho, this is the first time anyone has successfully combined light spin and color into a single design process while keeping image quality high and interference low. The potential applications are wide-ranging. This technology could be used in next-generation displays, secure data storage, or even in encryption systems that hide sensitive information in plain sight.
With its simple design and potential for commercial use, this ultra-thin metasurface hologram technology could transform how we interact with visual information—bringing us closer to a future where one screen can show many stories, all depending on how you look at it.
