26
PHYSICS OF THE IMPOSSIBLE
fraction only for red light. Their next step would be to use this technology to create a metamaterial that would bend red light entirely around
an object, rendering it invisible to that light.
Future developments along these lines may occur in the area of
"photonic crystals." The goal of photonic crystal technology is to create a
chip that uses light, rather than electricity, to process information. This
entails using nanotechnology to etch tiny components onto a wafer, such
that the index of refraction changes with each component. Transistors
using light have several advantages over those using electricity. For example, there is much less heat loss for photonic crystals. (In advanced
silicon chips, the heat generated is enough to fry an egg. Thus they must
be continually cooled down or else they will fail, and keeping them cool
is very costly.) Not surprisingly, the science of photonic crystals is ideally
suited for metamaterials, since both technologies involve manipulating
the index of refraction of light at the nanoscale.
INVISIBILITY VIA PLASMONICS
Not to be outdone, yet another group announced in mid-2007 that they
have created a metamaterial that bends visible light using an entirely
different technology, called "plasmonics." Physicists Henri Lezec, Jennifer Dionne, and Harry Atwater at the California Institute of Technology announced that they had created a metamaterial that had a
negative index for the more difficult blue-green region of the visible
spectrum of light.
The goal of plasmonics is to "squeeze" light so that one can manipulate objects at the nanoscale, especially on the surface of metals. The
reason metals conduct electricity is that electrons are loosely bound to
metal atoms, so they can freely move along the surface of the metal lattice. The electricity flowing in the wires in your home represents the
smooth flow of these loosely bound electrons on the metal surface. But
under certain conditions, when a light beam collides with the metal
surface, the electrons can vibrate in unison with the original light
beam, creating wavelike motions of the electrons on the metal surface
PHYSICS OF THE IMPOSSIBLE
fraction only for red light. Their next step would be to use this technology to create a metamaterial that would bend red light entirely around
an object, rendering it invisible to that light.
Future developments along these lines may occur in the area of
"photonic crystals." The goal of photonic crystal technology is to create a
chip that uses light, rather than electricity, to process information. This
entails using nanotechnology to etch tiny components onto a wafer, such
that the index of refraction changes with each component. Transistors
using light have several advantages over those using electricity. For example, there is much less heat loss for photonic crystals. (In advanced
silicon chips, the heat generated is enough to fry an egg. Thus they must
be continually cooled down or else they will fail, and keeping them cool
is very costly.) Not surprisingly, the science of photonic crystals is ideally
suited for metamaterials, since both technologies involve manipulating
the index of refraction of light at the nanoscale.
INVISIBILITY VIA PLASMONICS
Not to be outdone, yet another group announced in mid-2007 that they
have created a metamaterial that bends visible light using an entirely
different technology, called "plasmonics." Physicists Henri Lezec, Jennifer Dionne, and Harry Atwater at the California Institute of Technology announced that they had created a metamaterial that had a
negative index for the more difficult blue-green region of the visible
spectrum of light.
The goal of plasmonics is to "squeeze" light so that one can manipulate objects at the nanoscale, especially on the surface of metals. The
reason metals conduct electricity is that electrons are loosely bound to
metal atoms, so they can freely move along the surface of the metal lattice. The electricity flowing in the wires in your home represents the
smooth flow of these loosely bound electrons on the metal surface. But
under certain conditions, when a light beam collides with the metal
surface, the electrons can vibrate in unison with the original light
beam, creating wavelike motions of the electrons on the metal surface