A joint Australian-Chinese team has created the world’s thinnest hologram, paving the way for the integration of 3D holography into everyday electronics like smart phones, computers and TVs.
Conventional holograms modulate the phase of light to give the illusion of three-dimensional depth. But to generate enough phase shifts, those holograms need to be at the thickness of optical wavelengths.
The team from RMIT University and Beijing Institute of Technology (BIT) has broken this thickness limit with a 25 nm hologram based on a topological insulator material – a quantum material which holds the low refractive index in the surface layer but the ultrahigh 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.
RMIT Professor Min Gu says the nano-hologram is simple to make, can be seen without 3D goggles and is 1000 times thinner than a human hair.
“Conventional computer-generated holograms are too big for electronic devices but our ultrathin hologram overcomes those size barriers,” Gu said.
“Our nano-hologram is also fabricated using a simple and fast direct laser writing system, which makes our design suitable for large-scale uses and mass manufacture."
He says 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.
"From medical diagnostics to education, data storage, defence and cyber security, 3D holography has the potential to transform a range of industries and this research brings that revolution one critical step closer,” he said.
Dr Zengji Yue, who co-authored the paper with BIT’s Gaolei Xue, says 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.
“This involves shrinking our nano-hologram’s pixel size, making it at least 10 times smaller," said Yue. “But beyond that, we are looking to create flexible and elastic thin films that could be used on a whole range of surfaces, opening up the horizons of holographic applications.”
The research was published in the journal Nature Communications.
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