In December 1977, when Star Wars first lit up the screens of movie theatres around the world, cinemagoers watched as as a holographic Princess Leia pleaded for help from Obi-Wan Kenobi.
Today, she'd probably have sent a Snapchat instead. But a South Korean team has developed technology that would allow for a three-dimensional hologram to be beamed out of the head of a real-world R2D2.
In a paper, published in the journal Optics Express, they described a tabletop display system that allows multiple viewers to simultaneously see a hologram showing a 3D image as they walk around the table, viewable from any angle.
Viewing Window
"In the past, researchers interested in holographic display systems proposed or focused on methods for overcoming limitations in the combined spatial resolution and speed of commercially available, spatial light modulators," explained Yongjun Lim from the Electronics and Telecommunications Research Institute in South Korea, who led the research.
His group took a different approach, however, adding a novel viewing window design that uses parabolic mirrors to project the image. That would normally mean distortion, as parabolic mirrors aren't flat, so the team compensated with a special aspheric lens.
"As a result, multiple viewers are able to observe 3.2-inch size holograms from any position around the table without visual distortion,” said Lim.
Full Colour Experience
Right now, the team has only tested the system with monochrome green light, but a full colour experience is planned for the future - along with a few tweaks to solve some brightness issues.
"We are developing another version of our system to solve those issues and expect to have the next model in the near future, including enhancement of the color expression," said Lim.
“Many people expect that high quality holograms will entertain them in the near future because visualizations are increasingly sophisticated and highly imaginative due to the use of computer-aided graphics and recently-developed digital devices that provide augmented or virtual reality.”
