Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The analogue of a tsunami for telecommunication

23.12.2013
Development of electronics and communication requires a hardware base capable for increasingly larger precision, ergonomics and throughput.

For communication and GPS-navigation satellites, it is of great importance to reduce the payload mass as well as to ensure the signal stability. Last year, researchers from the Moscow State University (MSU) together with their Swiss colleagues performed a study that can induce certain improvements in this direction.

The scientists demonstrated (this paper was published in Nature Photonics) that the primary source of noise in microresonator based optical frequency combs (broad spectra composed of a large number of equidistant narrow emission lines) is related to non-linear harmonic generation mechanisms rather that by fundamental physical limitations and in principle reducible.

On December 22st, a new publication in Nature Photonics is appearing where they extend their results. Michael Gorodetsky, one of the co-authors of this paper, professor of the Physical Faculty of MSU affiliated also in the Russian Quantum Centre in Skolkovo, says that the study contains at least three important results: scientists found a technique to generate stable femtosecond (duration of the order of 10-15 seconds) pulses, optical combs and microwave signals.

Physicists used a microresonator (in this particular case, a millimeter-scale magnesium fluorite disk was used, where whispering-gallery electromagnetic oscillations may be excited, propagating along the circumference of the the resonator) to convert continuous laser emission into periodic pulses of extremely short duration. The best known analogous devices are mode-locked lasers that generating femtosecond, high-intensity pulses. Applications of these lasers range from analysis of chemical reactions at ultra-short timescales to eye-surgery.

"In mode-locked femtosecond lasers complex optical devices, media and special mirrors are normally used. However we succeeded in obtaining stable pulses just in passive optical resonator using its own non-linearity," -- Gorodetsky says. This allows, in future, to decrease drastically the size of the device.

The short pulses generated in the microresonator are in fact what is known as optical solitons (soliton is a stable, shape-conserving localized wave packet propagating in a non-linear medium like a quasiparticle; an example of a soliton existing in nature is a tsunami wave). "One can generate a single stable soliton circulating inside a microresonator. In the output optical fiber, one can obtain a periodic series of pulses with a period corresponding to a round trip time of the soliton." -- Gorodetsky explains.

Such pulses last for 100-200 femtoseconds, but the authors are sure that much shorter solitons are achievable. They suggest that their discovery allows to construct a new generation of compact, stable and cheap optical pulse generators working in the regimes unachievable with other techniques. In the spectral domain, these pulses correspond to the so-called optical frequency "combs" that revolutionized metrology and spectroscopy and brought to those who developed the method a Nobel Prize in physics in 2005 ( American John Hall and German Theodor Haensch received the Prize "for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique"). Currently existing comb generators are much larger and more massive.

At the same time, as the scientists show, a signal generated by such a comb on a photodetectors a high-frequency microwave signal with very low phase noise level. Ultra-low-noise microwave generators are extremely important in modern technology; they are used in metrology, radiolocation, telecommunication hardware, including satellite communications. Authors note that their results are critical for such applications as broadband spectroscopy, telecommunications, and astronomy.

Ilya Usov | EurekAlert!
Further information:
http://www.msu.ru

More articles from Physics and Astronomy:

nachricht Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center

nachricht Supermassive black hole model predicts characteristic light signals at cusp of collision
15.02.2018 | Rochester 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: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>