Researchers create hologram-like 3D suspended images

The scene in Star Wars: Episode IV — A New Hope, when through the bluish light of R2-D2's suspended 3D image, Princess Leia famously says, "Help me, Obi Wan Kenobi. You're my only hope," captures, arguably one of the most iconic moments from the Star Wars universe. With its graceful desperation, an undercurrent of hope and the impending possibility of adventure, the scene, in some ways, sets the mood of the movie. It inspires us to seek out those moments of adventure in our own lives, and the best part is that we might be able to do that with 3D images like the one in the scene.

Researchers at Brigham Young University in Provo, Utah, have managed to create such an image about the size of a postage stamp, according to Science. At the moment, the researchers' technology uses a single particle to draw these images, which means that it can only draw very small pictures, though they are high-resolution pictures. Daniel Smalley, an electrical engineer who worked on the research says that to make the images bigger, they would have to refine their prototype and create a system to manipulate 100 to 1000 particles at once.

Previously, we have used holograms — 2D image surfaces — and certain illusions to render 3D objects in a 2D space. However, the images created by them have to be viewed from a certain angle to be seen fully. But, the new 3D images actually occupy 3D space and can be viewed from all angles. It could be thought of as a 3D sculpture made of light.

According to Science magazine, this free space volumetric display works by first "trapping" a cellulose particle in a photophoretic "trap". The trap is essentially a suspension of some gas or liquid that has been exposed to a beam of the laser. The laser then guides the particle around while red, green, or blue lights illuminate it. This particle then becomes a single pixel, as it scatters the illuminating light. Thus, similar to the effect of waving a sparkler around, guiding the particle in a loop to scatter light in the same ways over and over again, blurs the pixels together to create an image made out of light. The group's research was published in Nature this past Jan.