Visitors Now:
Total Visits:
Total Stories:
Profile image
By Alton Parrish (Reporter)
Contributor profile | More stories
Story Views

Now:
Last Hour:
Last 24 Hours:
Total:

Filming Coupled Light and Electrons as They Travel Undercover

Sunday, November 13, 2016 14:43
% of readers think this story is Fact. Add your two cents.

(Before It's News)

In a breakthrough for future optical-electronic hybrid computers, scientists at EPFL have developed an ultrafast technique that can track light and electrons as they travel through a nanostructured surface.

When light couples to electrons on a surface, their concerted motion can travel as a wave guided by the surface geometry itself. These waves are known as “surface plasmons” and might be useful in telecommunications and future computing, where data will be shuttled across processors using light instead of electricity.

Aside from being more energy-efficient, these processors could be miniaturized down to the nanoscale to build high-resolution sensors and nanosized signal processing systems. But these processors would be built from stacking different layers of advanced materials and, so far, we don’t have a reliable way of tracking the guided light as it moves across their interfaces. EPFL scientists have now done exactly that using a new, ultrafast method.
 

An illustration of the experimental setup 
B4INREMOTE-aHR0cHM6Ly8xLmJwLmJsb2dzcG90LmNvbS8tR3ctWF9La0RGRHMvV0NqVXR6VUk4YkkvQUFBQUFBQUJRVmcvOGNIRWdBeG80STQtb2k4S21memtCZ0phVjNPTFh0UDNBQ0xjQi9zNjQwLzY1MngzNjclMkIlMjUyODElMjUyOS5qcGc=
Credit: © F.Carbone/EPFL
 

The breakthrough is published today in Nature Communications.

The lab of Fabrizio Carbone at EPFL led the project to create a tiny antenna array that would allow plasmons to travel across an interface. The array consisted of an extremely thin membrane of silicon nitride (50 nm thick) covered with an even thinner film of silver (30 nm thick). The scientists then “punched” a series of nano-holes through the surface that would act as the antennas — the plasmon “hotspots”.

The researchers then fired ultrafast laser pulses (light) onto the array to light up the antennas. With a controlled temporal delay, ultrashort electron pulses were then fired across the multilayer stack, to map the plasmons radiated by the antennas at the interface between the silver film and the silicon nitride membrane. Using an ultrafast technique called PINEM, which can “see” surface plasmons, even when they are bound to a buried interface, the scientists were able to actually film the propagation of the guided light and read its spatial profile across the film.

“Trying to see plasmons in these interfaces between layers is a bit like trying to film people in a house from the outside,” explains Fabrizio Carbone. “A regular camera won’t show you anything; but if you use microwave or a similar energy-tracking imaging, you can see right through the walls.”

The current paper paves the way for designing and controlling confined plasmonic fields in multilayered structures, which is key for future optoelectronic devices.

This work included contributions from the University of Glasgow, EPFL’s Interdisciplinary Center for Electron Microscopy, Boston University, the Barcelona Institute of Science and Technology, the Institució Catalana de Recerca i Estudis Avancats, and Trinity College (US). It was funded by the European Research Council (ERC), the Swiss National Science Foundation (NCCR-MUST), Trinity College, the Connecticut Space Grant Consortium, and MINECO (Spain).

Contacts and sources:
Nik Papageorgiou
École Polytechnique Fédérale De Lausanne (EPFL) 

 

Citation: Tom T. A. Lummen, Raymond J. Lamb, Gabriele Berruto, Thomas LaGrange, Luca Dal Negro, F. Javier García de Abajo, Damien McGrouther, Brett Barwick, Fabrizio Carbone. Shaping, imaging and controlling plasmonic interference fields at buried interfaces.Nature Communications 11 October 2016. DOI: 10.1038/NCOMMS13156

Report abuse

Comments

Your Comments
Question   Razz  Sad   Evil  Exclaim  Smile  Redface  Biggrin  Surprised  Eek   Confused   Cool  LOL   Mad   Twisted  Rolleyes   Wink  Idea  Arrow  Neutral  Cry   Mr. Green

Top Stories
Recent Stories

Register

Newsletter

Email this story
Email this story

If you really want to ban this commenter, please write down the reason:

If you really want to disable all recommended stories, click on OK button. After that, you will be redirect to your options page.