They may be tiny weapons, but the holography research group at Brigham Young University has figured out how to create lightsabers – green for Yoda and red for Darth Vader, naturally – with actual luminous beams rising from them. Inspired by the displays of science fiction, the researchers have also engi­neered battles between equally small versions of the Starship Enter­prise and a Klingon Battle Cruiser that incor­porate photon torpedoes launching and striking the enemy vessel that you can see with the naked eye.

“What you’re seeing in the scenes we create is real; there is nothing computer generated about them,” said lead researcher Dan Smalley. “This is not like the movies, where the lightsabers or the photon torpedoes never really existed in physical space. These are real, and if you look at them from any angle, you will see them existing in that space.” It’s the latest work from Smalley and his team of researchers who garnered national and inter­national attention three years ago when they figured out how to draw screenless, free-floating objects in space. These optical trap displays are created by trapping a single particle in the air with a laser beam and then moving that particle around, leaving behind a laser-illu­minated path that floats in midair; like a “a 3D printer for light.”

The research group’s new project goes to the next level and produces simple anima­tions in thin air. The deve­lopment paves the way for an immer­sive expe­rience where people can interact with holographic-like virtual objects that co-exist in their immediate space. “Most 3D displays require you to look at a screen, but our techno­logy allows us to create images floating in space – and they’re physical; not some mirage,” Smalley said. “This techno­logy can make it possible to create vibrant animated content that orbits around or crawls on or explodes out of every day physical objects.”

To demons­trate that principle, the team has created virtual stick figures that walk in thin air. They were able to demonstrate the inter­action between their virtual images and humans by having a student place a finger in the middle of the volu­metric display and then film the same stick finger walking along and jumping off that finger. The work overcomes a limiting factor to optical trap displays: wherein this tech­nology lacks the ability to show virtual images, Smalley and Rogers show it is possible to simulate virtual images by employing a time-varying per­spective projection backdrop. “We can play some fancy tricks with motion parallax and we can make the display look a lot bigger than it physically is,” Rogers said. “This metho­dology would allow us to create the illusion of a much deeper display up to theo­retically an infinite size display.” (Source: BYU)

Reference: W. Rogers & D. Smalley: Simulating virtual images in optical trap displays, Sci. Rep. 11, 7522 (2021); DOI: 10.1038/s41598-021-86495-6

Link: Electro-Holography Lab, Dept. of Electrical and Computer Engineering, Brigham Young University, Provo, USA