Colourful and highly interactive 3D holograms have been a staple of science fiction for many decades, yet researchers are still struggling to make this neat and functional method of displaying information a wide-spread reality.
The key problem here is that conventional, computer-generated holograms work by modulating the phase of light to give the illusion of depth, and to generate enough phase shifts, such holograms need to be at the thickness of optical wavelengths, thereby making them too large for electronic devices.
Now, however, an Australian-Chinese team of researchers had developed the world’s thinnest hologram that’s 1,000 times thinner than a human hair and is visible without wearing 3D goggles.
The hologram is manufactured using a simple and fast direct laser system, which makes it suitable for large-scale uses and mass-manufacture.
“Integrating holography into everyday electronics would make screen size irrelevant – a pop-up 3D hologram can display a wealth of data that doesn’t neatly fit on a phone or watch,” said team leader Professor Min Gu from the Royal Melbourne Institute of Technology (RMIT).
Integrating holograms into electronic devices could be useful in medical diagnosis, education, data storage, defence, cyber-security, and many other applications.
To break the thickness limit, researchers from the RMIT collaborated with colleagues from the Beijing Institute of Technology (BIT) had created a 25 nanometre hologram based on a topological insulator material – a novel quantum material that holds the low refractive index in the surface layer, but an ultra-high refractive index in the bulk.
The topological insulator thin film acts as an intrinsic optical resonant cavity, which can enhance the phase shifts for holographic imaging.
“The next stage for this research will be developing a rigid thin film that could be laid onto an LCD screen to enable 3D holographic display,” said project co-author Dr. Zengyi Yue.
Ultimately, the team hopes to create elastic films that could be fit onto almost any surface, opening the doors to three-dimensional holography anywhere, anytime.