A team of researchers from the Ecole Polytechnique Fédérale de Lausanne (EPFL) has successfully demonstrated, for the first time, that it is possible to control the speed of light – both slowing it down and speeding it up – in an optical fiber, using off-the-shelf instrumentation in normal environmental conditions. Their results, to be published in the August 22 issue of Applied Physics Letters, could have implications that range from optical computing to the fiber-optic telecommunications industry.
On the screen, a small pulse shifts back and forth – just a little bit. But this seemingly unremarkable phenomenon could have profound technological consequences. It represents the success of Luc Thévenaz and his fellow researchers in the Nanophotonics and Metrology laboratory at EPFL in controlling the speed of light in a simple optical fiber. They were able not only to slow light down by a factor of three from its well – established speed c of 300 million meters per second in a vacuum, but theyve also accomplished the considerable feat of speeding it up – making light go faster than the speed of light.
This is not the first time that scientists have tweaked the speed of a light signal. Even light passing through a window or water is slowed down a fraction as it travels through the medium. In fact, in the right conditions, scientists have been able to slow light down to the speed of a bicycle, or even stop it altogether. In 2003, a group from the University of Rochester made an important advance by slowing down a light signal in a room-temperature solid. But all these methods depend on special media such as cold gases or crystalline solids, and they only work at certain well-defined wavelengths. With the publication of their new method, the EPFL team, made up of Luc Thévenaz, Miguel Gonzaléz Herraez and Kwang-Yong Song, has raised the bar higher still. Their all-optical technique to slow light works in off-the-shelf optical fibers, without requiring costly experimental set-ups or special media. They can easily tune the speed of the light signal, thus achieving a wide range of delays.
Luc Thevenaz | EurekAlert!
The moon is front and center during a total solar eclipse
24.07.2017 | NASA/Goddard Space Flight Center
Superluminous supernova marks the death of a star at cosmic high noon
24.07.2017 | Royal Astronomical Society
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
24.07.2017 | Power and Electrical Engineering
24.07.2017 | Materials Sciences
24.07.2017 | Materials Sciences