This is an essay i wrote for The DuPont Challenge, for it's annual science essay competition.Our world today is quite different from what people in the past thought it would be. They might have expected that by now we would have flying cars and vacations in space, or we’d be bouncing around the world by teleport. [1] Today we do, however, possess emerging technology that may soon make holographic video a reality.
When one thinks of holograms, Princess Leia’s
desperate plea for help against an evil galactic empire may spring to
mind. This 35 year old idea is on its
way to becoming a reality. We've come a long way since the first static
holograms were transmitted over a television system in 1966.Scientists at the
University of Arizona in Tucson are in the midst of developing a new kind of
viewing technology that promises to surpass the much anticipated 3D television.
[2] With three dimensional television one sees two separate images: each eye
sees a separate image and the two are combined within the brain to create the illusion
of depth. But with a holographic television you would view 180 degrees of
whatever image was being projected. In the near future the general population
might be trading in their flat screen plasma television sets for a brand new
kind of home entertainment system using holograms.
To
make holographic recordings scientists are using a technique called
stereographic holography that has substantially decreased the data load and
number crunching required to process holographic digital information. This is
the root of what makes holographic movies possible. The basis of this technology
is that one image printed on a plastic based composite can be rapidly erased
and another three dimensional image rewritten in its place. [3] The composite
is called a photoreactive polymer, a plastic coated with a material that
converts light into electrical charges to store the image. The electrical
charges imprint the optical data onto the material to produce a realistic,
three dimensional image. This kind of fast paced rewriting technique has never
been used before. The process of putting holographic images onto the plastic
display starts with 16 cameras arranged in a semi -circle all capturing
different vantage points of an object in the middle. Then a flash of safe laser
light is blasted, much like the flash from light on a camera. This process is recorded
digitally.
After
the image is recorded it gets transmitted via wireless or Ethernet cable to the
display unit, where it appears on the photorefractive polymer. This kind of new
technology could drastically improve telepresence, which can be thought of as a
more physically realistic version of
Skype, Face Time, or Face Chat for Facebook. Imagine someone seeming to be actually in the
room with you instead of just a face on a computer screen. This has the
potential to be “the next big thing” and can revolutionize business meetings,
doctor-patient consultations, or military applications. Holography could have
applications in spying, guiding weapons, or any number of other defense
applications.
As
of now the refresh time of holography is around two seconds, already cut down
from four minutes from previous experiments at the University of Arizona.
Hopefully in the near future that time will be cut down to 30 frames per
second, the standard refresh time for video.
It
is the chemical composition of the polymer that makes the whole system
possible. The polymer is made by melting a composite between two glass plates.
The structure and composition of the polymer is a copolymer with a polyacrylic
back bone that was used to attach other chemical groups. A chromophore is added
to the compound to make the end product able to absorb and emit visible light.
This increases refractive index change, which in turn allows the information of
the holographic image to be written. The hologram is written by successively recording
approximately 120 holographic pixels, or “hogels,” side by side. After this, a plasticizer is added aswell. The
whole composite is chemically stable. Samples have been able to withstand use
for months and hundreds of rewrites without degeneration occurring. [4]
“This
is mostly a materials advance,” says optical scientist Michael Bove of the MIT
Media Lab. “The material is faster and more sensitive than what had previously
been reported.” [1]
Within the next several years it is hoped that
researchers will have completed at least a prototype of a video quality moving
hologram.
"It took us a while to make that first breakthrough, but as soon
as you have the first element of it working the rest often comes more rapidly.
What we are doing now is trying to make the model better,” says Nasser
Peyghambarian, chair of photonics and lasers at the University of Arizona’s
Optical Sciences department. [5] As for myself, I have a strong interest in the
field of Optics and plan to attend the University of Arizona as well. And who
knows, in the future I may take part in making this vision of holography
possible.
820 words
1. Lisa Grossman, (November 3, 2010), Wired Science,
Holographic Telecommuting May Soon be Possible,
(www.wired.com/wiredscience.2010/11/holographic-video/)
2. Stewart Bland, (December 16, 2010), Materials Today,
Coming Soon to a Screen near You,
(www.materialstoday.com/view/14710/coming-soon-to-a-screen-near-you/)
3. P.A Blanche, A. Bablumlan, R. Voorakaranam, C.
Christenson, W. Lin, T.Gu, D. Flores, P. Wang, W.-Y. Hsleh, M. Kathapeumal, B.
Rachwal, O. Sklddiqul, J. Thomas, R.A. Norwood, M. Yamamoto & N.
Peyghambarian, (November 4, 2010), Nature, Holographic Three-Dimensional
Telepresence Using Large-Area Photorefractive Polymer, Vol 468, pages 80-83
4. Jayan Thomas, Cory W. Christenson, Pierre-Alexandre
Blance, Michiharn Yamamoto, Robert A. Norwood, Nasser Peyghambarian, ( 2011),
Chemistry of Materials, Photoconducting Polymers for Photorefractive 3D Display
Applications, Issue 23, pages 416-429
5.Mike Steere, (October 7, 2008), CNN.com/technology,
Scientist: Holographic Television to Become Reality,
(http://articles.cnn.com/2008-10-06/tech/holographic.television_1_holographic-displays-hologram-technology?_s=PM:TECH)