Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New breed of optical soliton wave discovered

07.09.2016

Applied scientists led by Caltech's Kerry Vahala have discovered a new type of optical soliton wave that travels in the wake of other soliton waves, hitching a ride on and feeding off of the energy of the other wave.

Solitons are localized waves that act like particles: as they travel across space, they hold their shape and form rather than dispersing as other waves do.


Optical microcavities in which the solitons were created

Credit: Qi-Fan Yang/Caltech

They were first discovered in 1834 when Scottish engineer John Scott Russell noted an unusual wave that formed after the sudden stop of a barge in the Union Canal that runs between Falkirk and Edinburgh. Russell tracked the resulting wave for one or two miles, and noted that it preserved its shape as it traveled, until he ultimately lost sight of it.

He dubbed his discovery a "wave of translation." By the end of the century, the phenomenon had been described mathematically, ultimately giving birth to the concept of the soliton wave. Under normal conditions, waves tend to dissipate as they travel through space. Toss a stone into a pond, and the ripples will slowly die down as they spread out away from the point of impact. Solitons, on the other hand, do not.

In addition to water waves, solitons can occur as light waves. Vahala's team studies light solitons by having them recirculate indefinitely in micrometer-scale circular circuits called optical microcavities. Solitons have applications in the creation of highly accurate optical clocks, and can be used in microwave oscillators that are used for navigation and radar systems, among other things.

But despite decades of study, a soliton has never been observed behaving in a dependent -- almost parasitic--manner.

"This new soliton rides along with another soliton -- essentially, in the other soliton's wake. It also syphons energy off of the other soliton so that it is self-sustaining. It can eventually grow larger than its host," says Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics and executive officer for applied physics and materials science in the Division of Engineering and Applied Science.

Vahala likens these newly discovered solitons to pilot fish, carnivorous tropical fish that swim next to a shark so they can pick up scraps from the shark's meals. And by swimming in the shark's wake, the pilot fish reduce the drag of water on their own body, so they can travel with less effort.

Vahala is the corresponding author of a paper in the journal Nature Physics announcing and describing the new type of soliton, dubbed the "Stokes soliton." (The name "Stokes" was chosen for technical reasons having to do with how the soliton syphons energy from the host.) The new soliton was first observed by Caltech graduate students Qi-Fan Yang and Xu Yi. Because of the soliton's ability to closely match the position and shape of the original soliton, Yang's and Yi's initial reaction to the wave was to suspect that laboratory instrumentation was malfunctioning.

"We confirmed that the signal was not an artifact of the instrumentation by observing the signal on two spectrometers. We then knew it was real and had to figure out why a new soliton would spontaneously appear like this," Yang says.

The microcavities that Vahala and his team use include a laser input that provides the solitons with energy. This energy cannot be directly absorbed by the Stokes soliton -- the "pilot fish." Instead, the energy is consumed by the "shark" soliton. But then, Vahala and his team found, the energy is pulled away by the pilot fish soliton, which grows in size while the other soliton shrinks.

"Once we understood the environment required to sustain the new soliton, it actually became possible to design the microcavities to guarantee their formation and even their properties like wavelength -- effectively, color," Yi says. Yi and Yang collaborated with graduate student Ki Youl Yang on the research.

###

This work is described in a paper titled "Stokes solitons in optical microcavities," published on Sept. 5. The paper can be found online at http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3875.html. His research was funded by the Defense Advanced Research Projects Agency under the PULSE Program; NASA; the Kavli Nanoscience Institute; and the Institute for Quantum Information and Matter, a National Science Foundation Physics Frontiers Center supported by the Gordon and Betty Moore Foundation.

Media Contact

Robert Perkins
rperkins@caltech.edu
626-395-1862

 @caltech

http://www.caltech.edu 

Robert Perkins | EurekAlert!

More articles from Physics and Astronomy:

nachricht DGIST develops 20 times faster biosensor
24.04.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>