Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Progress in Nano-Optics

25.11.2013
To constrain individual light particles in a way as to control their movement on computer chips and nanostructures: This might lead to new developments in information technology. University of Würzburg physicists report on their progress in this field.

In recent years, computer engineers have no longer been able to increase the clock rate of conventional processors. This means that it is not possible to boost computer performance any further without recourse to certain tricks, such as the use of multiple processor cores.


Polarized light pulses are fed into a nano-antenna and guided along wires in specific charge wave patterns to be emitted elsewhere.

(Graphics: Thorsten Feichtner)

Therefore, researchers are looking for novel concepts. Optical circuits, which operate by means of light particles (photons), look promising in this context – not least because they seem to be suitable for data transmission between quantum computers. Such superfast computers are not yet available, but their implementation is a global research target.

Optical signal transmitted on the nanoscale

The study groups of Professor Bert Hecht and Professor Tobias Brixner at the University of Würzburg have now achieved an important step towards the development of optical circuits: The scientists were able to feed a light signal via an antenna into a waveguide and to have this signal emitted at the other end via another antenna.

What is special about this: The transmission of the optical signal was implemented in tiny structures that can be integrated in today's microelectronics: The antennas and the waveguide measure only a few hundred nanometers. Usually, photons cannot be controlled at such a small scale: "They are extremely unwilling to be confined in small places," Hecht explains. "Therefore, it is still very hard to combine photonic technologies with the silicon-based technology of conventional computer chips."

Success with oscillating plasmons

How did the researchers manage to control the photons? They worked with bound photons rather than free photons. These occur, under certain conditions, on the surface of well-conducting metals, such as gold. Incident light can generate there certain electron oscillations, also known as plasmons, which propagate along the metal to emit light elsewhere. Plasmons behave in a similar way to free photons, but they can be concentrated into very small places.

The Würzburg researchers have recently introduced the world's first simple plasmonic circuit in the prestigious journal "Physical Review Letters". It consists of an approximately 200-nanometer-long antenna, which efficiently captures free photons and converts them to plasmons. This light antenna is connected to a plasmon waveguide, consisting of two fine gold wires, which are about three micrometers long and run parallel to each other. There, the charge waves can spread in exactly two defined patterns – this phenomenon might be used in future to control the direction of movement of the plasmons, which is not possible in the case of electrons.

Strong damping in the circuit

As reported in the journal, the Würzburg researchers first show how the two charge wave patterns can be excited and how this excitation can be experimentally verified. However, the problem is that the plasmons are still strongly dampened on their way through the circuit. "This problem needs to be solved first before the principle can be translated into technological applications," says Hecht.

The physicists are aware that they have achieved only a small step towards the development of complete optical circuits. "Even so, our results will help to ensure that plasmonic waveguides will remain a highly exciting research topic in future," says Hecht.

"Multimode plasmon excitation and in-situ analysis in top-down fabricated nanocircuits", Peter Geisler, Gary Razinskas, Enno Krauss, Xiao-Fei Wu, Christian Rewitz, Philip Tuchscherer, Sebastian Goetz, Chen-Bin Huang, Tobias Brixner, and Bert Hecht, Phys. Rev. Lett. 111, 183901 (2013), DOI: 10.1103/PhysRevLett.111.183901

Contact person

Prof. Dr. Bert Hecht, Institute of Physics, University of Würzburg, T +49 (0)931 31-85863, hecht@physik.uni-wuerzburg.de

Prof. Dr. Tobias Brixner, Institute of Physical and Theoretical Chemistry, University of Würzburg, T +49 (0)931 31-86330, brixner@phys-chemie.uni-wuerzburg.de

Robert Emmerich | Uni Würzburg
Further information:
http://www.uni-wuerzburg.de

More articles from Physics and Astronomy:

nachricht Innovative LED High Power Light Source for UV
22.06.2017 | Omicron - Laserage Laserprodukte GmbH

nachricht Spin liquids − back to the roots
22.06.2017 | Universität Augsburg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>