There is a bit of a gap between what a hologram is, right now, and what you envision when you think of the word "hologram." When you picture a hologram, you imagine vivid, three-dimensional projections of an image. It could be of a map, schematics, or some wild thing out of the imagination of a filmmaker.
Holograms, in 2017, are nothing like that. You may have one on your driver's license, or depending on what country you're from, your currency. You may have a hologram at home trapped in a glass prism as a novelty gift. They might be 3D, but they don't move — or if they do, not by much. They're also not usually full color, instead rendered in one hue or some iridescent, limited spectrum of colors. In short, they're just not what you see in the movies. Not yet.
That's all about to change thanks to a concept at DAQRI, a startup that designs and builds augmented-reality devices, called Software Defined Light.
Light generally moves at one speed — aptly called "the speed of light." Albert Einstein made the discovery, and defined it as 300,000 kilometers per second. But the phrase "the speed of light" can be deceptive. That's how fast light travels in a vacuum, like it does in outer space, but light can move slower than that as well... in the right conditions.
A couple of elements eluded those hoping to accomplish this. First off, the math is complex — incredibly complex — so much so that without the proper algorithm, it would be impossible to make those computations in a timely manner. Secondly, you need the correct, adjustable physical element for the light to pass through. Having successfully cracked the algorithm and created their bi-phasic crystal phase element which can precisely generate an electric field using software, DAQRI were able to move into Software Defined Light.
Software Defined Light is when a light's speed is manipulated by a program. If we can use technology to control how fast light travels, we can use that to create more powerful, more functional, and more interesting holograms. In fact, it's the key to making holograms more like what you've seen in the movies.
Let's Back Up: Holograms 101
Currently, when you make a hologram, it's kind of like taking a picture... A photograph uses a light source, like sunlight, to capture the colors in a field of light and expose them to a piece of film. Believe it or not, your smartphone camera does the same thing, but with a sensor that converts colors in that field of light into digital pixel data.
A hologram is similar, but it can't use just any light source like sunlight. A hologram uses a beam of light waves that are all in phase with one another — aka, a laser.
One laser is split in two, reflected through a mirror, scattered through one or more lenses and shot at an object. That laser is then compared to the original laser beam from which it was split, called the "reference beam," and the differences between the two are recorded. That recording defines the size, shape, and textures of the object the beam was shot at. And that's basically it. That recording, when projected back onto a surface like a glass screen or a prism, creates a 3D still image. That's a hologram.
The use of DAQRI's Software Defined Light, compared with holograms as they exist readily today, is like the invention of modern filmmaking to the world of still pictures.
Software Defined Light and holograms
What Software Defined Light does is produce not one hologram, or two, but millions. Projecting one single, still hologram in full color requires about 150 million computations per second. A movie that you watch in theaters is projected at 24 frames, or 24 distinct images, per second. That means to project a full color hologram at a cinema-quality frame rate requires an incredible amount of computations in an incredibly short amount of time.
Software Defined Light, in use
The first consumer products to take advantage of Software Defined Light will be in market in late 2017, but it's already making a subtle introduction. Right now, DAQRI has "head-up displays" (or HUDs) on the road projecting useful information for drivers on the windshields of their vehicles. This means they don't have to take their eyes off the road to access important information, like the speed they're driving. The next iteration of the DAQRI Smart HUD™, using Software Defined Light, will have windshield projections at varying depths, so some information will appear to be right in front of you and farther down the road, at the same time.
This is just the beginning. With the help of five or six different depths, windshield holograms may be able to project 3D holograms that have a complete range of movement through space. Imagine, for example, a 3D arrow appearing in real space on the road that shows you, physically, which street to turn on for turn-by-turn navigation — an arrow that gets closer as the street does. Other potential applications include: improved navigation tools for self-driving cars, instantaneous 3D printing, high-resolution 3D medical imaging, more technologically advanced car headlamps, and holographic displays for everything from your TV to your smartwatch.
Seamus Blackley, DAQRI's principal scientist, says that because the entire form is created in one go, the resulting product doesn't suffer from weaknesses introduced by the "grain" that forms when an object is 3-D-printed by scanning a laser back and forth. Supporting structures that are required when building objects layer by layer are also unnecessary, he says, and larger objects should take about the same amount of time to print as smaller ones.
These were theoretical future applications, but they're a lot less theoretical than ever before. The work is being done today to make full color, full motion 3D holograms a reality in the near future.
Source and top image: DAQRI