Despite the first holographic video systems debuting at MIT back in 1990, their narrow viewing angle, bulky optics, and heavy computing requirements have kept holographic video displays from becoming commercially available.
Now, researchers at the Samsung Advanced Institute of Technology may have found a solution.
Traditional holograms are illuminated photographs that serve as the 2D windows looking onto 3D scenes. The holographic medium records the light field produced by an object, and can then recreate that light field to produce an image that we perceive as three-dimensional.
Existing holographic video devices are limited by the size of their components, both in terms of the physical space required as well as data size. While static holograms could record a wealth of data onto light-sensitive films, holographic video displays were limited due to the amount of data that needed to be encoded on the films. This resulted in either a very narrow viewing angle on a larger display or a larger angle on a miniscule display. The size drawback of video holographic devices was the bulky lens that was required to gather any scattered light from the display’s pixels in order to project a quality image.
To reduce the lens size, the research team used a geometric phase lens, thus saving space and reducing the display to a centimeter of thickness. The new slim-panel holographic video display uses a steering-backlight unit and a holographic video processor to address those issues.
The steering-backlight unit allows the viewing angle to be extended by 30 times its size without requiring additional pixels thanks to a beam deflector that can tilt the angles of coherent light beams from laser diodes within the device. The unit has a diffractive waveguide architecture, which enables the slim display.
Thanks to advances in computing, the holographic video processors used in these holographic devices can compute high quality holograms in real time with the use of a single chip. Replacing complex mathematical operations with lookup tables and reducing pixels to the smallest bits possible allowed the file size to be reduced, thus decreasing some of the computing concerns that holographic devices previously faced.
These advances come together to produce a prototype that possesses a 15-degree viewing angle at a distance of 1 meter on 10.1-inch display. The single-chip holographic video processor chip runs at nearly 140 billion operations per second in order to generate 4K color holographic images at 30 frames per second.
The researchers hope that these innovations will bring slim-panel three-dimensional video to the office, home and pocket environments.
To learn more, read the paper: Slim-panel holographic video display.