Scientists reveal world's thinnest 'floating' images that are 1,000 times narrower than a human hair

From Star Wars to Avatar, interactive 3D holograms are a staple in science fiction.
But the challenge for scientists trying to turn them into a reality is developing holograms that are thin enough to work with modern electronics.
Now, a pioneering team of researchers has created the world's thinnest hologram, which is 1,000 times thinner than a human hair.
The researchers hope their invention will pave the way towards integration of 3D holography into everyday electronics, including smart phones, computers at TVs.
The tiny hologram, which can be seen without 3D glasses, was created by an Australian-Chinese team from RMIT University in Melbourne.
Professor Min Gu, who led the study, said: 'Conventional computer-generated holograms are too big for electronic devices but our ultrathin hologram overcomes those size barriers.
'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.
'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.'
Professor Min Gu added that he believes holograms have the potential to be used in a huge range of sectors.
He added: '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.'
Most holograms control the phase of light to give the illusion of 3D depth.
But in order to generate enough phases of light, known as phase shifts, these holograms need to be at the thickness of optical wavelengths.
The team for RMIT has managed to break this thickness limit with a hologram that is just 25 nanometres wide.
This thinness was achieved by using a 'topological insulator material' – a novel material that 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 resonant cavity, which enhances the phase shifts for holographic imaging.
Dr Zengyi Yue, who co-authored the study, said: '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.
'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.'