It's not the first "floating" display that uses lasers to create a hologram-like image, but a team of Japanese researchers say their so-called Fairy Lights are a more practical solution than some of the alternatives. For one thing, they're able to strike a balance of providing tactile feedback while actually being safe to touch. Something that's proven difficult so far.
As the researchers explain in their paper, an earlier incarnation of the technology relied on a nanosecond laser to create bursts of plasma that, when fired in rapid succession, can effectively act as a floating display. The problem, as IEEE Spectrum notes, is that while those plasma bursts can deliver tactile feedback, they can also burn you.
The latest version developed by the researchers, on the other hand, uses a femtosecond laser to create a similar type of floating plasma display that's safe to touch. And while it won't burn you, the plasma will apparently still generate "shock waves" that will let you feel an "impulse on the finger as if the light has physical substance."
As you might expect, however, there are still some limitations to the technology, the biggest being that the displays themselves are currently no more than a centimetre square. But according to the researchers, they could be scaled up, and potentially used in an array of augmented reality or "aerial display" applications. You can check out the current state of the technology in the video below.