Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Future 'comb on a chip': NIST's compact frequency comb could go places

27.10.2011
Laser frequency combs—extraordinarily precise tools for measuring frequencies (or colors) of light—have helped propel advances in timekeeping, trace gas detection and related physics research to new heights in the past decade.

While typical lasers operate at only a single or handful of frequencies, laser frequency combs operate simultaneously at many frequencies, approaching a million for some combs. These combs have very fine, evenly spaced "teeth," each a specific frequency, which can be used like hash marks on a ruler to measure the light emitted by lasers, atoms, stars or other objects. But frequency combs are usually bulky, delicate lab instruments—about the size of a typical suitcase—and challenging to operate, which limits their use.

Now, researchers at the National Institute of Standards and Technology (NIST) have developed a compact laser frequency comb,* a step toward user-friendly and ultimately chip-based combs that could enable new applications in astronomical searches for Earth-like planets, high-capacity telecommunications, and—if other components are miniaturized as well—portable versions of the most advanced atomic clocks. Large frequency combs are best known as the "gears" in today's room-sized versions of these clocks.

NIST's prototype micro-comb consists of a low-power semiconductor laser about the size of a shoebox and a high-quality optical cavity just 2 millimeters wide. A miniature laser like those in DVD players might be substituted in the future to squeeze the whole comb apparatus onto a microchip.

Compact frequency combs have been developed recently by a number of other research groups, but NIST's is the first to use a cavity made of fused silica, or quartz, the most common optical material. This means it could be integrated easily with other optical and photonic components, lead author Scott Papp says.

A full-size frequency comb uses a high-power, ultrafast laser.** By contrast, the new compact version relies on a low-power laser and the cavity's unusual properties. The cavity is designed to limit light dispersion and confine the light in a small space to enhance intensity and optical interactions. The infrared laser light travels in a loop inside the cavity, generating a train of very short pulses and a spectrum of additional shades of infrared light. The small cavity, with no moving parts, offers insight into basic processes of frequency combs, which are difficult to observe in large versions.

Among its desirable features, NIST's compact comb has wide spacing between the teeth—10 to 100 times wider than that found in typical larger combs. This spacing allows scientists to more easily measure and manipulate the teeth. Of particular interest to project leader Scott Diddams, the widely spaced teeth can be individually read by astronomical instruments. Portable frequency combs can thus be used as ultrastable frequency references in the search for Earth-like planets orbiting distant stars.*** Portable frequency combs can also have many other important applications. For example, because a frequency comb can simultaneously generate hundreds of telecommunication channels from a single low-power source, a micro-comb might eventually replace individual lasers now used for each channel in fiber-optic telecommunications.

"We hope this is just the beginning and look forward to bigger and better developments," Diddams says. "In the short term we want to learn if this new type of comb can one day replace ultrafast laser-based combs used with NIST's best atomic clocks. And if not, its small size will likely lead to other opportunities."

The research was supported in part by the Defense Advanced Research Projects Agency.

* S.B. Papp and S.A. Diddams. Spectral and temporal characterization of a fused-quartz microresonator optical frequency comb. Physical Review A. Forthcoming.
** See background on optical frequency combs at http://www.nist.gov/public_affairs/releases/frequency_combs.cfm.

*** See 2009 Tech Beat article, "NIST, CU to Build Instrument to Help Search for Earth-like Planets," at http://www.nist.gov/public_affairs/techbeat/tb2009_1103.htm#cu

Laura Ost | EurekAlert!
Further information:
http://www.nist.gov

More articles from Physics and Astronomy:

nachricht Igniting a solar flare in the corona with lower-atmosphere kindling
29.03.2017 | New Jersey Institute of Technology

nachricht NASA spacecraft investigate clues in radiation belts
28.03.2017 | NASA/Goddard Space Flight Center

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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>