Lester Lefton Lester Lefton - Kent State University

Bending the
Laws of
Physics
Researchers receive $5.5 million to study
new optical material
By Melissa Edler, ’00
The idea that the focusing power
of optical elements comes from
their shape and how light bends
at the surface has been around
since the first century. It wasn’t
fully explained, however, until
the 17th century, when physicists
developed a theory behind
the phenomenon and predicted
that when electromagnetic
radiation, such as light, passes
between two media — like
from air to water — it bends or
refracts at a positive angle or to
the right side.
Today, this rule, named
Snell’s law, applies to every optical
object, including traffic lights,
headline ticker boards, microscopes,
telescopes, camcorders
and cameras.
Recently, though, scientists
have discovered a new type of
material called negative index
materials (NIMs), which defy
Snell’s law by bending light in
the opposite direction. “These
metamaterials are rewriting the
laws of optics, because they bend
light in a left-handed direction
compared to their positive, righthanded
counterparts,” says Dr.
Oleg Lavrentovich, director of
Kent State University’s Liquid
Crystal Institute®.
Kent State researchers,
along with a team of scientists
from several other institutions,
received a $5.5 million Multidisciplinary
University Research
Initiative (MURI) last April
from the Air Force Office of Scientific
Research to study these
unique metamaterials.
The notion of negative index
materials was considered wildly
speculative and unrealizable
when it was proposed more than
30 years ago. Recently, however,
scientists have learned how to
create NIMs in spectra invisible
to the human eye.
As part of a five-year MURI
project, Kent State researchers
and their colleagues plan to
break new ground by creating a
negative index material for the
visible and near-infrared spectrum
of light.
The concept of a material
with sub-wavelength resolution
is revolutionary in the fields of
science and technology. “The optical
behavior of negative index
materials is astonishing, and it
opens the door to a wide variety
of new and exciting applications,”
says Dr. Peter Palffy-Muhoray,
a Kent State professor of chemical-physics
at the Liquid Crystal
Institute and principal investigator
of the project.
Lenses made from NIMs,
which are not found anywhere
in nature, have unique physical
properties. A lens made from
negative index materials could
have resolution that is unlimited
by wavelength. In addition, these
metamaterials could reverse the
Doppler effect, potentially creating
zero reflectance from objects.
Photograph by G a r y H a r w o o d , ‘ 8 3
Dr. Peter Palffy-Muhoray is principal investigator on the project to study
negative index materials.
These negative index materials
have the potential to improve
devices in communications,
electronics, optics and medicine.
Specific applications include
creating flat, apertureless imaging
elements; “perfect” lenses
with super resolution; nondestructive
optical tweezers to
manipulate biological cells;
novel antennas; new beam
steering devices; sensors; novel
band gap materials; high-density
optical storage; vast improvements
to Magnetic Resonance
Imaging (MRI) scanning; and
the ability to store more information
on products such
as DVDs.
For more information about
this research, visit www.kent.
edu/magazine.
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