My watch list
my.chemeurope.com  
Login  

Using a microscopic ring to produce pulsed light

08-Jan-2016

© Tobias Kippenberg/EPFL

© Tobias Kippenberg/EPFL

Researchers funded by the SNSF have developed a laser signal generating device useful for telecommunications applications and chemical analysis.

Researchers funded by the Swiss National Science Foundation have made a chip-based device that can generate a laser signal with frequencies spaced in a comb-like fashion. Their work could be used in telecommunications applications and in chemical analysis

In general, light and water waves alike stretch out and dissipate as they move further and further away from their source. However, there is a type of wave that maintains its shape as it propagates: solitons.

Researchers funded by the Swiss National Science Foundation (SNSF) have successfully produced optical solitons – light waves that retain their shape – using a microresonator. The light is composed of a range of frequencies separated very precisely by the same distance, producing what physicists call a frequency comb, since it resembles the regular spacing between the teeth of a comb.

A new record

To generate the solitons, researchers at EPFL and the Russian Quantum Center in Moscow have used microresonators. "These microscopic ring-shaped structures are made from very fine silicon nitride," explains Tobias Kippenberg, the EPFL group leader. "They are capable of storing for a few nanoseconds the light of the laser to which they are coupled. This period of time is sufficient for the light to circumnavigate the ring thousands of times and to accumulate there, which strongly increases the intensity of the light." The interaction between the microresonator and the light becomes non-linear. The laser, which is normally continuous by nature, is converted into ultra-short pulses: solitons.

By adapting the parameters for manufacturing microresonators, the EPFL researchers additionally managed to generate a so-called soliton Cherenkov radiation. This broadens the frequency spectrum: the comb contains a greater number of teeth. Published in Science, the results have set a new record for this type of structure. The frequencies generated now extend over two thirds of an octave compared with the frequency of the laser.

Patent pending

"These results represent a promising advance for applications that require many widely spaced frequencies," says Kippenberg. In the context of optical communications, one single laser would be enough to create a range of individual frequencies which could separately carry information. Chemical spectroscopy and atomic timekeeping are other potential fields of application. "We have filed a patent, since there is potential for further technological developments," says Kippenberg.

Frequency combs, a discovery by Theodor Hänsch and John Hall that won them a Nobel Prize for Physics in 2005, are generally created using very large lasers. "The ability to produce optical frequency combs using small chips represents an interesting advance for making them more user-friendly," says Tobias Kippenberg.

Facts, background information, dossiers
  • solitons
  • microresonators
  • silicon nitride
More about Ecole Polytechnique Fédérale de Lausanne
  • News

    The holy grail of nanowire production

    Nanowires have the potential to revolutionize the technology around us. Measuring just 5-100 nanometers in diameter (a nanometer is a millionth of a millimeter), these tiny, needle-shaped crystalline structures can alter how electricity or light passes through them. They can emit, concentra ... more

    Intuition and failure as valuable ingredients in chemical research

    Researchers from the lab of NCCR MARVEL's deputy director Berend Smit and colleagues have developed a methodology for collecting the lessons learned from partially failed trials and incorrect hypotheses -- the experiments that didn't work. The researchers used machine learning to capture ch ... more

    Chirality in 'real-time'

    In nature, certain molecules with the same chemical composition, can exist in two different shapes that are mirrors images of each other, much like our hands. This property is known as "chirality" and molecules with different chirality are called enantiomers. Enantiomers can exhibit entirel ... more

  • Videos

    Water generates electricity (with a pinch of salt!)

    EPFL researchers have developed a system that generates electricity from osmosis with unparalleled efficiency. Their work, featured in "Nature", uses seawater, fresh water, and a new type of membrane just three atoms thick. more

    Stretchable electronics that quadruple in length

    EPFL researchers have developed conductive tracks that can be bent and stretched up to four times their original length. They could be used in artificial skin, connected clothing and on-body sensors. more

More about Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung
  • News

    Diamond watch components

    SNSF-funded researchers have developed a new technique for carving materials to create micromechanical systems. In particular, they have created a miniscule watch component out of synthetic single-crystal diamond. Diamond is very hard and elastic, a very good thermal conductor and highly tr ... more

    The first precise measurement of a single molecule's effective charge

    For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics. Electrical charge is one of the key properties that allows molecule ... more

    The key to chemical transformations

    Chemist Xile Hu is the winner of the National Latsis Prize for 2017. Hu, a professor at the École Polytechnique Fédérale de Lausanne, was recognised for his outstanding scientific career and his original contributions to the fundamental understanding of catalysis. Catalysis is a field of ch ... more

  • Videos

    The key to chemical transformations

    Chemist Xile Hu is awarded the National Latsis Prize 2017, Xile Hu is Professor of Chemistry at the Swiss Federal Institute of Technology in Lausanne (EPFL). He is honored for his impressive scientific career and outstanding research on the fundamental understanding of catalysis. more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE