Holograms are a science-fiction staple from Star Trek's holodeck to the famous scene in Star Wars where a holographic Princess Leia implores, "Help me, Obi-Wan Kenobi." But the reality has never lived up to the dream.
That might change. Scientists at the Massachusetts Institute of Technology built a tiny device that contains a grid of 4,096 miniature antennas (64 by 64) that steer beams of infrared light to create patterns. Their so-called phased array was able to generate an image -- in this case a tiny MIT logo -- and "float" it a few millimeters out in front of the grid.
It's the first time anyone has built an array with so many components, as previous attempts only managed 16. It's also the first device of its kind that can steer each beam from an individual antennae in both the vertical and horizontal direction, making it possible to create three-dimensional pictures.
"At a basic level we're showing that not only can you steer beams actively but also generate new and arbitrary patterns," said Michael Watts, a professor in the Research Laboratory of Electronics at MIT. That opens up a number of possibilities in holography as well as imaging devices such as biomedical sensors, akin to radar. Communications is also a possibility, since fine control of light waves can reduce interference and noise.