In the original Star Wars movie, R2D2 projects an image of Princess Leia in distress saying “Help me, Obi Wan Kenobi, you are my only hope.” T he professor of electrical and computer engineering from Brigham Young University (EE. UU.) And holography expert Daniel Smalley wanted to create the same type of 3D imaging the film. They have succeeded and it is much better than a hologram. The work has been published in the journal Nature.
“We refer to this colloquially as the Princess Leia project. Our group is on a mission to take 3D samples from science fiction and bring them to life . We have created a screen that is capable of doing that,” says Smalley.
The iconic image of Princess Leia is not a hologram but a 3D image floating in the air, that you can walk around and see from all angles, that is, a volumetric image. Examples of volumetric images include the 3D screens that Tony Stark interacts with in Ironman or the huge projection table of images from the movie ‘Avatar’.
And is that a holographic screen scatters light only on a 2D surface . If you are not looking at that surface, you will not see the 3D image because you must look at the scattering surface to see the image. A volumetric screen has small scattering surfaces spread over a three-dimensional space, the same space occupied by the three-dimensional image, hence when looking at the image, we are also looking at the dispersions. For this reason, a volumetric image can be viewed from any angle.
To achieve this, they devised a free-space volumetric viewing platform, which produces full-color aerial volumetric images with 10-micron image dots. “We are using a laser beam to catch a particle, and then we can direct the laser beam to move the particle and create the image”, clarifies Erich Nygaard, co-author of the work.
Print in the air
According to the authors, the easiest way to understand what they are doing is to think of the images they create as 3D printed objects. “ This screen is like a 3D printer for light . You are actually printing an object in space with these little particles,” says Smalley.
The scientists created a butterfly that appears to flutter on a finger, a prism the university logo and the image of a student who imitates Leia in the scene from the Star Wars movie.
Smalley’s team was the first to use optical trapping and color effectively. His method of retaining particles and illuminating them with colorful lasers is truly novel.
“We are providing a method to make a volumetric image that can create the images that we imagine we will have in the future,” concludes Smalley.
Reference: DE Smalley, E. Nygaard, K. Squire, J. Van Wagoner, J. Rasmussen, S. Gneiting, K. Qaderi, J. Goodsell, W. Rogers, M. Lindsey, K. Costner, A. Monk, M. Pearson, B. Haymore & J. Peatross. A photophoretic-trap volumetric display . Nature , 2018 DOI: 10.1038 / nature25176
Image credit: Dan Smalley Lab
