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The Future of Optics

the future of optics

© H. Benisty /LCFIO et T. Stomeo /Univ St Andrews

A nanophotonic structure used to direct optical information, here two channels carried by two similar wavelengths. This type of system could one day be used in electronic chips.

Ever heard of plasmonics? This is a specific field of nanophotonics. If the latter studies the behavior of light on the nanometer scale in general, plasmonics investigates how light surfs on the surface of metals using the metal's free electrons—and this has researchers very excited.
It got a boost in 1998, when Thomas Ebbesen, today director of the Institute of Supramolecular Science and Engineering (ISIS),1 discovered a completely unexpected phenomenon he dubbed “extraordinary optical transmission” or the “photon sieve.”
“A photon sieve is a network of holes pierced in a nanostructured metal surface, at regular intervals and with diameters of 100-200 nm, in other words considerably smaller than the wavelength of visible light,” explains Henri Benisty, of LCFIO.2 “When you illuminate this surface, the quantity of light that comes out on the other side is much larger than the fraction that struck the holes. Even the light that falls next to the holes is channeled to the other side of the sample.” Plasmons manage to convey this light into the holes instead of spoiling or reflecting it.
The researchers are trying to make use of these unconventional properties to perform new manipulations of light at nanometric scales. “We're hoping to bring about ultra-localized modifications, far more than what is possible with a laser, for applications in lithography, in biology—for example in the compartments inside a cell—or even to write information at smaller scales on a hard disk,” says Benisty.
In addition, plasmonics could improve the efficiency of photovoltaic cells by improving the capture of light and its further conversion within nanostructured materials.
In the field of telecommunications, the use of photons is in rapid expansion, being exploited in much shorter connections within circuit boards for their high throughput. In fact, optical connections should soon be able to second electronic connections, even in electronic circuits (“chips”) themselves. “Ultra-densely packed electronic connections are negatively affected by interference and consumption issues,” explains Benisty. “We're trying to build nanometrically controlled architectures where optics could be used to transmit the largest or most energy-hungry information flows inside chips.”

Notes :

1. Institut de Science et d'Ingénierie Supramoléculaires (CNRS / Université de Strasbourg).
2. Laboratoire Charles Fabry de l'Institut d'Optique (CNRS / Université Paris-XI).

Contacts :

Henri Benisty,


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