Innovative device makes production of holographic-displays possible at a fraction of cost of today’s experimental monochromatic displays.
Researchers at the Massachusetts Institute of Technology (MIT) have come up with a new technique that could soon enable manufacturers to produce notebooks that would be able to display holograms such as those known from the Star Wars saga.
In an article published in the journal Nature, an MIT graduate student Daniel Smalley describes a prototype colour holographic-video display built on a $10 optical chip.
“Everything else in there costs more than the chip,” said Smalley’s thesis advisor, Michael Bove, a principal research scientist at the MIT's Media Lab and head of its Object-Based Media Group. “The power supplies in there cost more than the chip. The plastic costs more than the chip.”
The display has a resolution similar to that of a standard-definition TV and can update video images up to 30 times per second, which is fast enough to produce the illusion of continuous motion.
The chip at the core of the device is made of lithium niobate. It is a minuscule crystal that diffracts light in a similar way a 3D object does, so it appears differently when viewed from various angles.
Beneath the crystal’s surface are microscopic channels known as waveguides that confine the light travelling through them. Each waveguide is also coated with a conducting metallic material capable of producing an acoustic wave.
Smalley builds on the work started by MIT professor Stephen Benton (died in 2003), who had created the first holographic-video displays using a technique known as acousto-optic modulation and later used big tellurium dioxide crystals to do the job.
Compared to Benton’s pioneering work, Smalley’s device is considerably tinier as it doesn’t require a separate waveguide for each colour. “Until now, if you wanted to make a light modulator for a video projector, or an LCD panel for a TV or something like that, you had to deal with the red light, the green light and the blue light separately,” said Michal Bove. “That’s inefficient, because the filters, even if they were perfect, would throw away two-thirds of the light. But second, it reduces either the resolution or the speed at which the modulator can operate.”
Daniel Smalley believes the most exciting thing about his chip is the waveguide-based platform, which represents a major departure from every other type of spatial light modulator used for holographic video right now
“This has the potential to be a game-changer, and I’m really serious about that,” commented Pierre Blanche, an assistant research professor at the University of Arizona who is also researching holographic video. “It’s a huge achievement.”
Scientists estimate that a holographic monitor using the technology could be built for less than 500 US dollars (GBP320), excluding light sources.
Holographic video is even more realistic than standardl3D images, as they appear differently as the viewer moves around, in a same way real-life objects do.