A 3D shape, seemingly made of light, floats in mid-air.
It’s a familiar image in fictional visions of the future.
But that fictional future may be a lot closer
and a lot more real than you think.
"We here at the Electro-Holography Group at
Brigham Young University
have created a display that is
very much like the displays of science fiction."
But despite the similarity to the holograms
of Hollywood films,
these displays are different…
"This image is not a hologram.
We’ve demonstrated here that we can see
it from the front,
we can see it from the back, and, in reality,
we can see it from almost any angle.
And that separates it from technologies like holograms
that can only be seen from a certain range of angles."
Scientists call these science fiction-worthy displays 'volumetric images'.
"A volumetric image is essentially
an image that is taking up three-dimensional space.
And our approach is that we’re actually using
a laser beam to trap a particle
and then we can move that,
we can basically steer that beam around
to move the particle and create the image."
Like when you swing a sparkler around,
a particle moving fast enough
looks like a solid line
and can be moved to form a shape.
"We can think about this image like a 3D printed object.
A single point was dragged sequentially
through all these image points
and as it did it scattered light.
And the accumulated effect
of all that scattering and moving
was to create this 3D image in space
that is visible from all angles."
As well as taking up real 3D space,
the images created by this single particle
and a few low-cost lasers
can be incredibly high-resolution,
up to 1,600 dots per inch.
Although they’re very detailed, the images
created so far have been quite small
and they remain difficult to capture on video.
Because of the video's frame rate,
the display appears to flicker here,
but to the human eye and to still cameras,
the image appears whole.
Rather than being used in epic space battles
or to communicate with alien races,
these kinds of three-dimensional visualizations
may instead be used to train medical professionals
for advanced procedures.
They could also be used in aviation,
providing busy air traffic controllers with
more accurate and intuitive visual maps
of how planes are moving around airports.
To reach that point though, researchers will have to first
master the trapping and moving
of multiple particles simultaneously
in order to scale up the images to sizes larger
than the tip of your thumb.
Until then, we'll just have to settle for
experiencing the future
in miniature.
