Holographic technology to power pocket-sized video projectors
December 28, 2004, Cambridge, England--Nic Lawrence, Edward Buckley, Adrian Cable, and Peter Mash, researchers within the Photonics and Sensors Group at the University of Cambridge Department of Engineering, are developing holographic technology that is expected to power a new generation of pocket-sized digital video projectors.
The concept of a holographic projector is not new, but some technical issues have prevented development of an actual product based on this technology:
-- Holograms are extremely complex objects mathematically, and calculating them fast enough for video applications is very difficult; even the most powerful computers would take minutes to generate a hologram to project just a single video frame.
-- The projected images produced by holograms tend to be speckled and of very low quality.
-- The lasers that are required to illuminate the holograms have, until very recently, been very expensive and limited in availability.
In the Photonics and Sensors Group in the Department of Engineering, liquid-crystal-on-silicon (LCOS) devices have been developed for real-time holographic displays and applications in telecom systems. Several major breakthroughs have been made, making possible the generation and display of high-quality holograms at video frame rates, using a single custom chip that Lawrence and his team have designed. A hologram pattern, which to the naked eye looks like a collection of random dots, is displayed on a LCOS microdisplay. The hologram patterns are calculated by a proprietary "hologram chip" so that when the microdisplay is illuminated by laser light, the light interferes with itself in a complex manner through the physical process of diffraction which, when carefully controlled, results in the formation of a large, high quality projected image on, for example, a screen or a wall. Unlike a conventional video projector, heavy, bulky lenses are not required; diffraction does all the work for you, and the projected image is sharp and in focus at any distance.
Light Blue Optics has been set up as a spin-out company in order to commercialize this research. Light Blue Optics is currently developing relationships with a number of industrial partners and welcome contact from companies potentially interested in integrating this technology with their products. At present, Light Blue Optics has a lab-based demonstrator, which converts a standard composite video signal into high-quality 2D holographic video in real time. The hologram generation engine runs in a commercially available field-programmable gate array chip. Other processing platforms including low-power digital signal processing ICs are also under development.