With their ubiquity in science fiction, and carrying the potential to transform smart devices, communication, gaming, and entertainment, holograms would be a major technological advancement, if we could find an easier way of projecting them.

A team at the University of St. Andrews have found that 'Holographic Metasurfaces' (HMs) and Organic Light Emitting Diodes (OLEDs) give a simpler and more compact approach that is potentially cheaper and easier to apply, overcoming the main barriers to hologram technology being used more widely.

Organic light-emitting diodes are thin film devices widely used to make the colored pixels in mobile phone displays and some TVs. As a flat and surface-emitting light source, OLEDs are also used in emerging applications such as optical wireless communications, biophotonics, and sensing, where the ability to integrate with other technologies makes them good candidates to realize miniaturized light-based platforms.

A holographic metasurface is?a thin, flat array of tiny structures called meta-atoms—the size of roughly a thousand of the width of a strand of hair. They are designed to manipulate light's properties, and can make holograms and their uses span diverse fields, such as data storage, anti-counterfeiting, optical displays, high numerical aperture lenses, optical microscopy, and sensing.

This, however, is the first time both have been used together to produce the basic building block of a holographic display.

Researchers found that when each meta-atom is carefully shaped to control the properties of the beam of light that goes through it, it behaves as a pixel of the HM. When light goes through the HM, at each pixel, the properties of the light are slightly modified.

Thanks to these modifications, it is possible to create a pre-designed image on the other side, exploiting the principle of light interference, whereby light waves create complicated patterns when they interact with each other.