2018 may be so far disappointing in terms of flying cars and faster-than-light drives, but US scientists have brought us one step closer to Star Wars-esque holograms — real 3D images produced in thin air.
In a study published in the journal Nature, the team describes the creation of an “Optical Trap Display”, a platform capable of producing 3D visual representations of objects. The sculpture-like images are in full colour, high-resolution, and can coexist with solid objects in the same physical space.
Daniel Smalley, lead author of the study, from Brigham Young University in Utah, says the technique is distinct from other holographic technology because the resultant image “is a real, material object.”
Holographic images are usually created through the complex manipulations of light, using a 2D film that scatters light to create a 3D image. But pesky limitations such as narrow viewing angles or the need for special headgear can take away some of the sci-fi excitement.
“In order to see the image you must be looking at the film,” Smalley explains, meaning if you change your viewing position, the image disappears. “Our technology allows you to see the image from virtually every angle.”{%recommended 6572%}
The technique uses a light field to trap and move a small particle through space. The light field itself is nearly invisible to the human eye, but the particle is illuminated by red, green and blue laser light as it speeds around to map out the surface of the represented object. It thus creates the appearance of a solid 3D object with a range of colours and fine details. If the particle zooms around fast enough, the image can even appear to move like a video.
“It is good to see the demonstration that this concept is technically practical,” says Lei Wang, a PhD student in nano-holography at the Australian National University who was not involved in the study. Wang comments, however, that the technique may prove expensive in both computational power and the running costs of high powered lasers — so we won’t be sending interstellar distress holograms like Princess Leia just yet.
In addition, this technology can currently only produce small images, although the researchers anticipate that they can be scaled up by manipulating multiple particles at the same time.
According to Smalley, this technology will then “be capable of creating the displays of science fiction — just as we have imagined them.”