INVISIBILITY 27
(called plasmons), and these wavelike motions beat in unison with the
original light beam. More important, one can "squeeze" these plasmons so that they have the same frequency as the original beam (and
hence carry the same information) but have a much smaller wavelength. In principle, one might then cram these squeezed waves onto
nanowires. As with photonic crystals, the ultimate goal of plasmonics
is to create computer chips that compute using light, rather than electricity.
The Cal Tech group built their metamaterial out of two layers of
silver, with a silicon-nitrogen insulator in between (with a thickness of
only 50 nm), which acted as a "waveguide" that could shepherd the direction of the plasmonic waves. Laser light enters and exits the apparatus via two slits carved into the metamaterial. By analyzing the
angles at which the laser light is bent as it passes through the metamaterial, one can then verify that the light is being bent via a negative
index.
THE FUTURE OF METAMATERIALS
Progress in metamaterials will accelerate in the future for the simple
reason that there is already intense interest in creating transistors that
use light beams rather than electricity. Research in invisibility can
therefore "piggyback" on the ongoing research in photonic crystals
and plasmonics for creating replacements for the silicon chip. Already
hundreds of millions of dollars are being invested in creating replacements for silicon technology, and research in metamaterials will benefit from these research efforts.
With breakthroughs occurring in this field every few months, it's
not surprising that some physicists see some sort of practical invisibility shield emerging out of the laboratory perhaps within a few decades.
In the next few years, for example, scientists are confident that they
will be able to create metamaterials that can render an object totally
invisible for one frequency of visible light, at least in two dimensions.
To do this would require embedding tiny nano implants not in regular
(called plasmons), and these wavelike motions beat in unison with the
original light beam. More important, one can "squeeze" these plasmons so that they have the same frequency as the original beam (and
hence carry the same information) but have a much smaller wavelength. In principle, one might then cram these squeezed waves onto
nanowires. As with photonic crystals, the ultimate goal of plasmonics
is to create computer chips that compute using light, rather than electricity.
The Cal Tech group built their metamaterial out of two layers of
silver, with a silicon-nitrogen insulator in between (with a thickness of
only 50 nm), which acted as a "waveguide" that could shepherd the direction of the plasmonic waves. Laser light enters and exits the apparatus via two slits carved into the metamaterial. By analyzing the
angles at which the laser light is bent as it passes through the metamaterial, one can then verify that the light is being bent via a negative
index.
THE FUTURE OF METAMATERIALS
Progress in metamaterials will accelerate in the future for the simple
reason that there is already intense interest in creating transistors that
use light beams rather than electricity. Research in invisibility can
therefore "piggyback" on the ongoing research in photonic crystals
and plasmonics for creating replacements for the silicon chip. Already
hundreds of millions of dollars are being invested in creating replacements for silicon technology, and research in metamaterials will benefit from these research efforts.
With breakthroughs occurring in this field every few months, it's
not surprising that some physicists see some sort of practical invisibility shield emerging out of the laboratory perhaps within a few decades.
In the next few years, for example, scientists are confident that they
will be able to create metamaterials that can render an object totally
invisible for one frequency of visible light, at least in two dimensions.
To do this would require embedding tiny nano implants not in regular