A research team led by Professor Junsuk Rho of the Pohang University of Science and Technology (POSTECH) has developed a metasurface display technology that enables holograms to display multiple images based on the observer’s viewing angle.
A key factor in creating cinematic and realistic 3D holograms is the ability to distinctly display the objects depending on the viewer’s position. One of the challenges in generating realistic 3D holograms is the need to control light dispersion according to the angle. To address this, Rho’s team opted to use metasurfaces – artificial nanostructures capable of precisely manipulating the characteristics of light. As these metasurfaces are extremely thin and lightweight, they would be useful for applications in miniaturized displays, such as virtual and augmented reality devices.
Using the metasurfaces, they designed a system that controls light to convey only a specific phase of information at a given angle, resulting in diverse images based on the angle of incidence. Under testing, the metasurface generated distinct 3D holographic images at angles of both +35˚ and -35˚ for left-circular polarization. The holographic display demonstrated an extensive viewing angle of 70 degrees (±35 degrees), enabling observers to perceive the three-dimensional hologram from various directions. The team was able to achieve the production of different images for incident light by using a single metasurface, contingent on the specific polarization.
“We have successfully achieved an effective display from diverse angles,” stated Rho. “We anticipate this technology will make significant contributions to the commercialization of technology in virtual and augmented reality displays, encrypted imaging, information storage, and other applications.”