Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Physicists from Johannes Gutenberg University Mainz develop a multifunctional storage device for light

29.07.2009
Monolithic microresonator enables the controlled coupling of light and matter / Publication in Physical Review Letters

Light is intangible and, in addition, it travels at great velocity. Nevertheless, it can be confined to a very small space by controllably inserting light into a microscopic container surrounded by reflective walls. The light will then be stored by continuous reflections and cannot escape.

In the scientific domain, such a small reflective microcavity is termed a microresonator. These microresonators find applications in all areas where the interaction between light and matter shall be enhanced and studied in a controlled manner. An important area of usage is, for example, the laser diode, which has revolutionized telecommunications and optical data storage in the past few decades.

Due to the high velocity of light - in just one second light travels more than seven times around the earth - the number of reflections per second in microresonators reaches up to a few trillion. If, in this situation, the light is to be captured for as little as a millionth of a second, each of the one million reflections that occur during this time may only induce a loss of about one millionth of the light power. An every-day metallic mirror loses a few percent of the light power per reflection and would thus fall short of this requirement by more than a factor of ten thousand.

A further property of microresonators can be explained best through comparison with a string of a musical instrument: akin to the way in which the latter can only vibrate at distinct frequencies which depend on their length, the dimensions of a microresonator determine the specific optical frequencies or colors it can store. However, if, like for the example of a laser, the stored light is to be coupled to atoms, its frequency has to be precisely tuned to the relevant atomic species. The lack of such a possibility of tuning a microresonator is thus a deficiency that impairs many important applications.

At the Johannes Gutenberg University Mainz a team of physicists led by Professor Arno Rauschenbeutel have now for the first time realized a microresonator that combines all the desired properties, i.e., long storage time, small volume, and tunability to arbitrary optical frequencies, in a single monolithic device. As reported by the research team in the current edition of the scientific journal Physical Review Letters, to accomplish this feat, it is enough to heat and stretch a standard glass fiber until it reaches about half the diameter of a human hair and then to create a bulge-shaped structure with the help of a laser. Light within this structure is continually reflected at the surface of the fiber and thus travels in a spiral path around the fiber axis. In doing so, the light cannot escape along the fiber because the diameter of the fiber reduces on either side of the structure.

Similar to the motion of a charged particle stored in a magnetic bottle, i.e., a particular spatially varying magnetic field, the light oscillates back and forth along the fiber between two turning points. For this reason, this novel type of microresonator realized by the physicists in Mainz is referred to as a bottle resonator. Tuning the bottle resonator to a specific optical frequency can be accomplished by simply pulling both ends of the supporting glass fiber. The resulting mechanical tension changes the refractive index of the glass, so that depending on the tension, the round-trip of the light is lengthened or shortened.

Because of its exceptional characteristics and its simple design based on glass-fiber technology, the bottle resonator opens up numerous areas of application. "At Mainz University, we aim to use this novel multifunctional microresonator for coupling minute light fields, consisting of single photons, with single atoms," explains Professor Rauschenbeutel from the QUANTUM, Quantum-, Atom-, and Neutron-Physics-Division at the Institute of Physics of Johannes Gutenberg University in Mainz. "If that were successful, one could realize, for example, a glass fiber based quantum interface between light and matter," according to Rauschenbeutel. This would then be an important contribution towards quantum communication and the future realization of a quantum computer.

Original publication:
M. Pollinger, D. O' Shea, F. Warken, and A. Rauschenbeutel: Ultrahigh-Q Tunable Whispering-Gallery-Mode Microresonator, in: Phys. Rev. Lett. 103, 053901 (2009), doi: 10.1103/PhysRevLett.103.053901; http://link.aps.org/doi/10.1103/PhysRevLett.103.053901.
Further information:
Professor Dr Arno Rauschenbeutel
Institute of Physics
QUANTUM - Quantum-, Atom-, and Neutron-Physics-Division
Johannes Gutenberg University Mainz
Tel.: +49 6131 39-20203
Fax: +49 6131 39-26979
email: rauschenbeutel@uni-mainz.de

Petra Giegerich | idw
Further information:
http://link.aps.org/doi/10.1103/PhysRevLett.103.053901
http://www.uni-mainz.de

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>