The Princess Leia Project is turning Star Wars holograms into science

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Feb 6, 2018

No Star Wars fan will ever forget the scene in which R2-D2 projects a hologram image of a glowing blue Princess Leia desperate for help from Obi-Wan. The fiction didn’t exactly translate to science. Holograms were thought to be something that might stay in a sci-fi galaxy far, far away—until now.

Daniel Smalley, an electrical and computer engineering professor at BYU who is also obsessed with holography, is blurring the lines between science and fiction with a futuristic method of 3D image projection that seeks to emulate the droid’s visual way of replaying messages.

“We refer to this colloquially as the Princess Leia project,” Smalley, who recently published a paper on his far-out “Princess Leia Project” in Nature, said. “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.”

The thing about that floating image of Leia is that it actually isn’t a hologram. Holograms only scatter light at a 2D surface, so you can only see the image in 3D if you’re looking at the scattering surface. Before hardcore Star Wars fans start shooting laser beams in this general direction, such a 3D light-ghost suspended in midair is actually a volumetric image that has micro scattering surfaces dispersed in the 3D space the image appears in.

You’ve seen it in other movies besides Star Wars. Think Tony Stark’s infinitely cool 3D displays in the Iron Man and Avengers movies or the Gamemakers’ table that projects images of the arena in The Hunger Games.

Replicating this sci-fi tech—otherwise known as a photophoretic-trap volumetric display—meant coming up with a free-space platform for it.

“Free-space volumetric displays, or displays that create luminous image points in space are capable of producing images in ‘thin air’ that are visible from almost any direction,” Smalley explained in the paper.

What is even cooler about these images, as he goes on to explain, is that these images aren’t prone to clipping, which can restrict the utility of all types of displays that involve a light scattering surface and a separate image point. With a platform he calls an Optical Trap Display, Smalley and his team can create image points in space and produce otherworldly full-color graphics that were, until recently, only the stuff of movie special effects.

Optical Trap Display works kind of like a 3D printer. It traps a particle with a laser beam, with the trap and particle then scanned through a display volume and illuminated by red, green and blue light. It essentially uses a laser beam to trap a particle and then make an image materialize by moving it around, which is so Jedi. What you see is a 3D image that is surprisingly hi-res and beats out any other space-age methods previously attempted with light fields and holographics.

The technology hasn’t reached droid status yet. It can only produce tiny images so far, like a planet that can rest on the tip of your finger, but you can be sure you’ll be seeing a whole Millennium Falcon flying through thin air sooner than you think.

(via BYU News)