For anyone who grew up watching Star Trek, real life holograms are a dream come true. Meeting Vic Fontaine or singing a duet with the Doctor, who wouldn’t want that opportunity? But of course, Trek fans aren’t the only ones looking forward to the day when we will have real-life holograms—holograms that you can see, speak to, and even touch. This tech would revolutionize gaming, allowing us to run alongside our NPCs into battle; it would help doctors develop medical treatments, allowing them to project 3D versions of tumors and injuries in real-time; and, well, it would basically transform nearly every aspect of our society.
And we just came a step closer to the day when such holograms are a reality.
Researchers in Japan have just created holograms that you can physically feel, and they even respond to human touch. Of course, you may not really want to touch the holograms. You see, these images are created by powerful, ultra-quick lasers. And as we all know, lasers + skin = burning
However, the team was able to avoid damaging participants’ skin by reducing the duration of the lasers’ bursts. They found that pulses between 50 milliseconds and 1 second were perfect. They resulted in optimized sense of touch and, well, not burning.
According to principal investigator Yoichi Ochiai, touching the holograms feels a little like sandpaper, though other participants described the sensation as an electric shock. Perhaps not the most pleasurable experience, certainly not like shaking hands with a neighbor, but a great leap forward all the same. A paper outlining the work, and its various implications, has been accepted at ACM Transactions on Graphics.
The work comes from the University of Tsukuba’s Digital Nature Group (DNG) and involves what is known as “femtosecond lasers.” These are lasers that operate in short bursts. In this case, they transmit in bursts of 30 to 270 femtoseconds (1 femtosecond is equal to a quadrillionth of a second, so we are talking about very, very tiny scales).
Ultimately, operating the lasers at such excessive speeds means the holograms can respond to touch in real-time. In order to maximize the effect, these lasers are combined with a spatial light modulator, a mirror, and a Galvano scanner (which is used in order to precisely target the lasers). A camera underneath is also used to monitor participants’ movements and enhance the simulation.
Using these methods, the team was able to create responsive shapes up to 1 cm cubed. True, that is rather small; however, this is also just the early stages. If developed, the technique could be expanded and used to create any number of objects.
Imagine being able to learn about history with interactive guides, visit a virtual reality petting zoo, or playing any number of games that involve actually touching the characters in-game.
That said, it will be some time before this technology is anything like what we see in Star Trek. Current existing forms of this technology have debilitating limitations. Most notably, the quality of the holograms themselves. Though this has been improved by the most recent development, the flickering shapes of light still look like, well, flickering shapes of light. Also, the size of the 3D images is an issue (a 1 centimeter person is an absurdly small person). Then there is the viewing angle, as most holograms have to be viewed from a specific point in order to avoid distortion. And the speed that the frames are capable of changing are also among the many restrictions.
However, much of this is improving, as it’s now possible to fix a few of these problems by modifying the spatial light modulators—the technology responsible for directing the light into the proper points in three dimensional space, making the images come to life—and improving the response rate.
So. It may take some time, but future generations may very well live in a rather unworldly place.