Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum leap for phonon lasers

22.02.2010
Physicists take a big step toward practical sound-based laser analogues

Physicists have taken major step forward in the development of practical phonon lasers, which emit sound in much the same way that optical lasers emit light.

The development should lead to new, high-resolution imaging devices and medical applications. Just as optical lasers have been incorporated into countless, ubiquitous devices, a phonon laser is likely to be critical to a host of as yet unimaginable applications.

Two separate research groups, one located in the US and the other in the UK, are reporting dramatic advances in the development of phonon lasers in the current issue of Physical Review Letters. The papers are highlighted with a Viewpoint by Jacob Khurgin of Johns Hopkins University in the February 22 issue of Physics (http://physics.aps.org).

Light and sound are similar in various ways: they both can be thought of in terms of waves, and they both come in quantum mechanical units (photons in the case of light, and phonons in the case of sound). In addition, both light and sound can be produced as random collections of quanta (consider the light emitted by a light bulb) or orderly waves that travel in coordinated fashion (as is the case for laser light). Many physicists believed that the parallels imply that lasers should be as feasible with sound as they are with light.

While low frequency sound in the range that humans can hear (up to 20 kilohertz) is easy to produce in either a random or orderly fashion, things get more difficult at the terahertz (trillions of hertz) frequencies that are the regime of potential phonon laser applications. The problem stems from the fact that sound travels much slower than light, which in turn means that the wavelength of sound is much shorter than light at a given frequency. Instead of resulting in orderly, coherent phonon lasers, miniscule structures that can produce terahertz sound tend to emit phonons randomly.

Researchers at Caltech have overcome the problem by assembling a pair of microscopic cavities that only permit specific frequencies of phonons to be emitted. They can also tune the system to emit phonons of different frequencies by changing the relative separation of the microcavities.

The group from the UK's University of Nottingham took a different approach. They built their device out of electrons moving through a series of structures known as quantum wells. As an electron hops from one quantum well to the next, it produces a phonon. So far, the Nottingham group has not demonstrated a true phonon lasing, but their system amplifies high-frequency sound in a way that suggests it could be it a key component in future phonon laser designs.

Regardless of the approach, the recent developments are landmark breakthroughs on the route to practical phonon lasers. Phonon lasers would have to go a long way to match the utility of their optical cousins, but the many applications that physicists have in mind already, including medical imaging, high precision measurement devices, and high-energy focused sound, suggest that sound-based lasers may have a future nearly as bright as light lasers.

James Riordon | EurekAlert!
Further information:
http://www.aps.org

More articles from Physics and Astronomy:

nachricht NASA's Fermi catches gamma-ray flashes from tropical storms
25.04.2017 | NASA/Goddard Space Flight Center

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

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>