An aerial for light
Austrian physicists report unusual light-metal interaction
A team under Professor Franz Aussenegg at the University of Graz in Austria is looking into unusual interactions between light and submicroscopic metal particles. The physicists’ findings represent a major advance towards the development of improved data storage media and optical sensors. They also confirmed theoretical predictions and merited publication in 13 international scientific journals. These are the impressive results of a two-year project funded by the Austrian Science Fund (FWF) that has been investigating the nano-cosmos.
“There’s plenty of room at the bottom,” said American Nobel Prizewinner Richard P. Feynman back in 1959. By “the bottom” he meant the world of things that are too small to see, and his point is proved by today’s computer chips, which are constantly becoming smaller yet can process increasing amounts of data, and the steadily growing capacity of CDs and DVDs. However data processing in ever tinier dimensions calls for new technologies. One of these, nano-optics, which uses light, is being researched into by Prof. Aussenegg’s team at the University of Graz Institute for Experimental Physics in Austria.
“For physical reasons guiding light with the help of lenses, mirrors or prisms is no longer possible when you get down to millionths of millimetres — the nanoworld,” said the Institute’s director, Aussenegg. “But this is the level where light — or to be more precise, optoelectrical fields — can be led through solid materials. In principle, it’s like guiding radio and TV signals through aerials and cables.” This is possible because light enters into a fascinating interaction with metal at the nanometre level. It is no longer reflected but instead excites electrons near the surface of the metal, causing them to oscillate. For a short time the light is “captured“ in the metallic structure, as an electrical field. If this “surface plasmon” state lasts long enough the optoelectrical oscillations in the metal can be channelled, as though they were travelling along a nanoscopic wire. This is crucial to the prospects of nano-optics as a practical technology.
The Graz project, completed in December 2002, succeeded in demonstrating that it is possible to influence the duration of the oscillating state of electrons near the surface of a grating-like structure of metal particles that are a few millionths of a millimetre apart from each other. The FWF backed project investigated the influence of the precise dimensions of gold and silver gratings. It provided convincing confirmation of the theoretical prediction that the right ratio of the spacing of the metal particles and their size to the wavelength of the light would quadruple the duration of the oscillation.
The team’s findings have laid the groundwork for the use of light as an alternative to electrotechnology in telecommunications engineering, data processing and data storage. The results have already opened the way for improved data storage media and optical sensors. The researchers’ work has attracted widespread attention, as shown by an article published on 24 October in the online version of Britain’s Economist magazine which spoke of a “significant step towards properly integrated optoelectronics”. Again and again, the origins of industrial revolutions have lain in fundamental research, and the breakthrough in Graz could be the start of another.
Bildunterschrift: The principle of the surface plasmon: light spreads outwards on a nanoscopic metal surface similarly to a wave in water.
Alexandra Stolba | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...