.PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News Number 770 March 23, 2006 by Phillip F. Schewe, Ben Stein
TWO-DIMENSIONAL LIGHT, OR PLASMONS, can be triggered when light strikes a patterned metallic surface. Plasmons may well serve as a proxy for bridging the divide between photonics (high throughput of
data but also relatively large circuit dimensions---1 micron) and electronics (relatively low throughput but tiny dimensions---tens of nm). One might be able to establish a hybrid discipline, plasmonics, in which light is first converted into plasmons, which then propagate in a metallic surface but with a wavelength smaller than the original light; the plasmons could then be processed with
their own two-dimensional optical components (mirrors, waveguides, lenses, etc.), and later plasmons could be turned back into light or into electric signals. To show how this field is shaping up, here are a few plasmon results from that great international physics bazaar, the APS March Meeting, which took place last week in
Baltimore.
1. Plasmons in biosensors and cancer therapy: Naomi Halas (Rice Univ., halas@rice.edu) described how plasmons excited in the surface of tiny gold-coated rice-grain-shaped particles can act as powerful, localized sources of light for doing spectroscopy on nearby bio-molecules. The plasmons's electric fields at the curved ends of the rice are much more intense than those of the laser light used to excite the plasmons, and this greatly improves the speed and accuracy of the spectroscopy. Tuned a different way, plasmons on nanoparticles can be used not just for identification but also for the eradication of cancer cells in rats.
2. Plasmon microscope: Igor Smolyaninov (Univ. Maryland, smoly@eng.umd.edu) reported that he and his colleagues were able to image tiny objects lying in a plane with spatial resolution as good as 60 nm (when mathematical tricks are applied, the resolution becomes 30 nm) using plasmons that had been excited in that plane by laser light at a wavelength of 515 nm. In other words, they achieve microscopy with a spatial resolution much better than diffraction would normally allow; furthermore, this is far-field microscopy---the light source doesn't have to be located less than a light-wavelength away from the object. This work is essentially a Flatland version of optics. They use 2D plasmon mirrors and lenses to help in the imaging and then conduct plasmons away by a waveguide.
3. Photon-polariton superlensing and giant transmission: Gennady Shvets (Univ. Texas, gena@physics.utexas.edu) reported on his use of surface phonons excited by light to achieve super-lens (lensing with flat-panel materials) microscope resolutions as good as one-twentieth of a wavelength in the mid-infrared range of light. He and his colleagues could image subsurface features in a sample,
and they observed what they call "giant transmission," in which light falls on a surface covered with holes much smaller than the wavelength of the light. Even though the total area of the holes is only 6% of the total surface area, 30% of the light got through, courtesy of plasmon activity at the holes.
4. Future plasmon circuits at optical frequencies: Nader Engheta (Univ. Pennsylvania, engheta@ee.upenn.edu) argued that nano-particles, some supporting plasmon excitations, could be configured to act as nm-sized capacitors, resistors, and inductors---the basic elements of any electrical circuit. The circuit in this case would be able to operate not at radio (10^10 Hz) or microwave (10^12 Hz) but at optical (10^15 Hz) frequencies.
This would make possible the miniaturization and direct processing of optical signals with nano-antennas, nano-circuit-filters, nano-waveguides, nano-resonators, and may lead to possible applications in nano-computing, nano-storage, molecular signaling, and molecular-optical interfacing.
I know this has nothing to do with the war in Iraq, but could the universe get any stranger?
Will we have two dimensional blogs?
TWO-DIMENSIONAL LIGHT, OR PLASMONS, can be triggered when light strikes a patterned metallic surface. Plasmons may well serve as a proxy for bridging the divide between photonics (high throughput of
data but also relatively large circuit dimensions---1 micron) and electronics (relatively low throughput but tiny dimensions---tens of nm). One might be able to establish a hybrid discipline, plasmonics, in which light is first converted into plasmons, which then propagate in a metallic surface but with a wavelength smaller than the original light; the plasmons could then be processed with
their own two-dimensional optical components (mirrors, waveguides, lenses, etc.), and later plasmons could be turned back into light or into electric signals. To show how this field is shaping up, here are a few plasmon results from that great international physics bazaar, the APS March Meeting, which took place last week in
Baltimore.
1. Plasmons in biosensors and cancer therapy: Naomi Halas (Rice Univ., halas@rice.edu) described how plasmons excited in the surface of tiny gold-coated rice-grain-shaped particles can act as powerful, localized sources of light for doing spectroscopy on nearby bio-molecules. The plasmons's electric fields at the curved ends of the rice are much more intense than those of the laser light used to excite the plasmons, and this greatly improves the speed and accuracy of the spectroscopy. Tuned a different way, plasmons on nanoparticles can be used not just for identification but also for the eradication of cancer cells in rats.
2. Plasmon microscope: Igor Smolyaninov (Univ. Maryland, smoly@eng.umd.edu) reported that he and his colleagues were able to image tiny objects lying in a plane with spatial resolution as good as 60 nm (when mathematical tricks are applied, the resolution becomes 30 nm) using plasmons that had been excited in that plane by laser light at a wavelength of 515 nm. In other words, they achieve microscopy with a spatial resolution much better than diffraction would normally allow; furthermore, this is far-field microscopy---the light source doesn't have to be located less than a light-wavelength away from the object. This work is essentially a Flatland version of optics. They use 2D plasmon mirrors and lenses to help in the imaging and then conduct plasmons away by a waveguide.
3. Photon-polariton superlensing and giant transmission: Gennady Shvets (Univ. Texas, gena@physics.utexas.edu) reported on his use of surface phonons excited by light to achieve super-lens (lensing with flat-panel materials) microscope resolutions as good as one-twentieth of a wavelength in the mid-infrared range of light. He and his colleagues could image subsurface features in a sample,
and they observed what they call "giant transmission," in which light falls on a surface covered with holes much smaller than the wavelength of the light. Even though the total area of the holes is only 6% of the total surface area, 30% of the light got through, courtesy of plasmon activity at the holes.
4. Future plasmon circuits at optical frequencies: Nader Engheta (Univ. Pennsylvania, engheta@ee.upenn.edu) argued that nano-particles, some supporting plasmon excitations, could be configured to act as nm-sized capacitors, resistors, and inductors---the basic elements of any electrical circuit. The circuit in this case would be able to operate not at radio (10^10 Hz) or microwave (10^12 Hz) but at optical (10^15 Hz) frequencies.
This would make possible the miniaturization and direct processing of optical signals with nano-antennas, nano-circuit-filters, nano-waveguides, nano-resonators, and may lead to possible applications in nano-computing, nano-storage, molecular signaling, and molecular-optical interfacing.
I know this has nothing to do with the war in Iraq, but could the universe get any stranger?
Will we have two dimensional blogs?
posted by madtom at 7:52 PM
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