Advances in holograph technology

A case of being in the right place at the right time has enabled a longsought breakthrough in 3D technology that may soon make the #holographic depictions of Star Wars’ R2D2 a reality. It all started when Swinburne researcher Dr Xiangping Li’s work revealed the tiny refractive index of #graphene in 2013. But it wasn’t until his group leader, Professor Min Gu, attended an optics conference in China later that year that they realised the implications of this research for 3D holographs. The material’s tiny refractive index makes it possible to achieve a pixel size as small as 0.5 micrometre — somewhere between the size of a bacteria and a virus — when recording a hologram. This property has many potential applications, but in China, Gu heard researchers from the Beijing Institute of Technology describe the challenge posed by pixel size for creating holographic images with a large viewing angle. The Beijing group had been researching holograph technology for many years but had come up against the challenge of how to increase the viewing angle to create images that could be viewed without glasses or other external assistance. The viewing angle is a measure of the angular distance from viewing the hologram front-on to side-on before the image distorts. “I asked them how they could increase the viewing angle and they talked about reducing the pixel size,” says Gu. “We realised, ‘Ah, we can do that now!’. Digital holographic images have conventionally been produced using spatial modulators (SLMs) which can only produce pixels as small as 10 micrometres. Using femtosecond laser pulses to reduce graphene oxide without heat and taking advantage of the material’s newly discovered tiny refractive index, the team at Swinburne’s Centre for Micro-Photonics created high-resolution images with light-bending pixels 1/20th the size of SLMs.

http://www.swinburne.edu.au/news/latest-news/2016/11/advances-in-holograph-technology.php