Star Wars-style glowing 3D images projected into thin air by US engineers
Image credit: Daniel Smalley Lab Nate Edwards/BYU Photo
Researchers based at Brigham Young University have refined a technique which positions and illuminates particles with laser beams to create 3D images in thin air.
These images bear a striking resemblance to the bright, floating 3D projections we frequently see in science-fiction films and television shows, such as Princess Leia’s 3D recorded message calling for help, kick-starting Luke Skywalker’s adventures in the first ‘Star Wars’ film.
Contrary to popular belief, Princess Leia’s famous message is not a hologram. A holographic display scatters light at a 2D surface, so unless the viewer is looking directly at that surface, they cannot see the hologram. The floating 3D images we see in ‘Star Wars’ and other films such as ‘Iron Man’ and ‘Avatar’ are closer to “volumetric images”.
A volumetric image is an unbounded 3D image suspended in free space which can be viewed from every angle. Unlike holographic displays, volumetric displays have many small scattering surfaces distributed in the 3D space that the image fills.
Now, researchers at Brigham Young University, led by electrical and computer engineer Professor Daniel Smalley, have developed a method for “printing” light in space to project 3D images.
“We refer to this colloquially as the Princess Leia project,” said Smalley. “Our group has a mission to take the 3D displays of science fiction and make them real. We have created a display that can do that.”
They managed to create a free-space volumetric display platform, which is capable of projecting full-colour 3D images in mid-air. Smalley and his team achieved this with photophoretic optical tracking, whereby laser beams are used to trap and steer a cellulose particle into position. Many illuminated particles are used to build up a 3D image.
“This display is like a 3D printer for light,” said Smalley. “You’re actually printing an object in space with these little particles.”
Other researchers have created some volumetric imagery in the past, although the Brigham Young team is the first to exploit optical trapping and colour so effectively.
To demonstrate their display platform, the Brigham Young team have produced detailed, glowing 3D images of the globe, a prism, a butterfly, the university’s logo, a member of the team crouched over like Princess Leia in her 3D message, and Charmander (a Pokémon).
“We’re providing a method to make a volumetric image that can create the images we imagine we’ll have in the future.”