Hologram. Image: Haider Butt |
Scientists have generated holograms from carbon nanotubes, for
the first time, which could lead to much sharper holograms with a vastly
increased field of view.
The researchers from the University of Cambridge’s Centre of
Molecular Materials for Photonics and Electronics (CMMPE) have harnessed the
extraordinary conductive and light scattering abilities of these tubes—made
from several sheets of carbon atoms rolled into a cylinder—to diffract high-resolution
holograms.
Carbon nanotubes are one billionth of a meter wide, only a few nanometers,
and the scientists have used them as the smallest ever scattering elements to
create a static holographic projection of the word Cambridge.
Many scientists believe that carbon nanotubes will be at the
heart of future industry and human endeavor, with anticipated impact on
everything from solar cells to cancer treatments, as well as optical imaging.
One of their most astonishing features is strength—about 100 times stronger
than steel at one-sixth the weight.
The work on using these nanotubes to project holograms, the 2D
images that optically render as three-dimensional, has been published in Advanced Materials.
“Smaller pixels allow the diffraction of light at larger angles—increasing
the field of view. Essentially, the smaller the pixel, the higher the resolution
of the hologram,” says Haider Butt from CMMPE, who conducted the work along
with Yunuen Montelongo.
“We used carbon nanotubes as diffractive elements—or pixels—to
produce high-resolution and wide field of view holograms.”
The multiwalled nanotubes used for this work are around 700
times thinner than a human hair, and grown vertically on a layer of silicon in
the manner of atomic chimney stacks.
The researchers were able to calculate a placement pattern that
expressed the name of this institution using various colors of laser light –
all channeled out (scattered) from the nanoscale structures.
For Haider Butt this is just the start—as these pixels and their
subsequent displays are not only of the highest resolution, but ultrasensitive
to changes in material and incoming light.
“A new class of highly sensitive holographic sensors can be
developed that could sense distance, motion, tilt, temperature and density of
biological materials,” says Butt.
“What’s certain is that these results pave the way towards utilizing
nanostructures to producing 3D holograms with wide field of view and the very
highest resolution.”
For the researchers, there are two key next steps for this
emerging technology. One is to find a less expensive alternative to nanotubes,
which are financially prohibitive: “Alternative materials should be explored
and researched, we are going to try zinc oxide nanowires to achieve the same
effects.”
The other is to investigate movement in the projections.
Currently, these atomic scale pixels can only render static holograms. Butt and
his team will look at different techniques such as combining these pixels with
the liquid crystals found in flat-screen technology to create fluid displays—possibly
leading to changeable pictures and even razor-sharp holographic video.
Source: University of Cambridge
