Researchers mixed OLEDs with metasurfaces to venture holograms. The technique allows simpler, less expensive, and smaller displays.
New research from the University of St Andrews is improving holographic technology, with potential applications in smart gadgets, communication, gaming, and entertainment. In a paper posted in the journal Light, Science and Application, physicists from the School of Physics and Astronomy reported the introduction of a new optoelectronic device that mixes Holographic Metasurfaces (HMs) with Organic Light-Emitting Diodes (OLEDs).
Until now, holograms have usually been created using lasers. The St Andrews team, however, showed that pairing OLEDs with HMs gives a more compact and simple approach. This method isn’t only easier to execute but also much less costly, handling one of the main challenges that has limited wider use of holographic technology.
OLEDs are thin-film devices already not common in mobile phone displays and in some televisions, in which they generate colored pixels. Due to, they are flat and release light throughout the surface, OLEDs are also promising for emerging fields which include optical wireless communication, biophotonics, and sensing. Their flexibility and capacity to incorporate with different components cause them to well-suited for growth miniaturized, light-based systems.
A holographic metasurface is a thin, flat layer formed of nanoscale structure called meta-atoms, each about a thousandth the width of a human hair. These structures are planned to control the behavior of light in particular ways. They can create holograms and have potential uses in data storage, anti-counterfeiting technologies, optical displays, high-resolution microscopy, and sensing.
Creating holographic pictures
Researchers discovered that after every meta- atom is carefully formed to control the properties of the beam of light that goes through it, it behaves as a pixel of the HM. When light goes by the HM, at every pixel, the features of the light are barely modified.
Thanks to those changes, it’s is possible to generate a pre-designed image on the opposite side, leveraging the principle of light interference, wherein light waves generate complex patterns when they interact with every other.
Expert views and applications
Professor Ifor Samuel, from the School of Physics and Astronomy, stated: “We are thrilled to show this new direction for OLEDs. By mixing OLEDs with metasurfaces, we also open a new way of producing holograms and shaping light.”
Andrea Di Falco, professor in nano-photonics on the School of Physics and Astronomy, stated: “Holographic metasurfaces are one of the most flexible material platforms to manipulate light. With this work, we have removed one of the technological limitations that save the adoption of metamaterials in everyday applications. This step forward will allow a step change in the architecture of holographic presentations for rising applications, for example, in virtual and augmented reality.”
Professor Graham Turnbull, from the School of Physics and Astronomy, stated: “OLED displays typically need thousands of pixels to generate a simple picture. This new approach permits a complete image to be projected from a single OLED pixel!”
Until now, researchers could only make very simple shapes with OLEDs, which limited their usability in some programs. However, this leap forward gives a route toward a miniaturized and quite integrated metasurface display.
