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 Magnetic nano-imaging on a table top
20.04.2018 | Georg-August-Universität Göttingen

nachricht New record on squeezing light to one atom: Atomic Lego guides light below one nanometer
20.04.2018 | ICFO-The Institute of Photonic Sciences

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: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>