Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Frequency comb’ spectroscopy proves to be powerful chemical analysis tool

17.03.2006


Physicists at JILA have designed and demonstrated a highly sensitive new tool for real-time analysis of the quantity, structure and dynamics of a variety of atoms and molecules simultaneously, even in minuscule gas samples. The technology could provide unprecedented capabilities in many settings, such as chemistry laboratories, environmental monitoring stations, security sites screening for explosives or biochemical weapons, and medical offices where patients’ breath is analyzed to monitor disease.


The new JILA technique uses infrared laser light in many different colors, or frequencies, to identify trace levels of different molecules at the same time. For example, water molecules (blue) and ammonia molecules (green) absorb light at very specific characteristic frequencies. The pattern of frequencies absorbed forms a "signature" for identifying the molecules and their concentrations.



Described in the March 17 issue of Science,* the new technology is an adaptation of a conventional technique, cavity ring-down spectroscopy, for identifying chemicals based on their interactions with light. The JILA system uses an ultrafast laser-based "optical frequency comb" as both the light source and as a ruler for precisely measuring the many different colors of light after the interactions. The technology offers a novel combination of a broad range of frequencies (or bandwidth), high sensitivity, precision and speed. A provisional patent application has been filed.

JILA is a joint institute of the National Institute of Standards and Technology (NIST), a non-regulatory agency of the U.S. Department of Commerce, and the University of Colorado at Boulder.


"What a frequency comb can do beautifully is offer a powerful combination of broad spectral range and fine resolution," says NIST Fellow Jun Ye, who led the work described in the paper. "The amount of information gathered with this approach was previously unimaginable. It’s like being able to see every single tree of an entire forest. This is something that could have tremendous industrial and commercial value."

Frequency combs are an emerging technology designed and used at JILA, NIST and other laboratories for frequency metrology and optical atomic clocks, and are being demonstrated in additional applications. NIST/JILA physicist John (Jan) Hall shared the 2005 Nobel Prize in physics in part for his contributions to the development of frequency combs [www.nist.gov/public_affairs/newsfromnist_frequency_combs.htm]. In the application described in Science, the frequency comb is used to precisely measure and identify the light absorption signatures of many different atoms and molecules.

The JILA system described in Science offers exceptional performance for all four of the primary characteristics desired in a cutting-edge spectroscopic system:

  • The system currently spans 125,000 frequency components of light, or 100 nanometers (750-850 nm) in the visible and near-infrared wavelength range, enabling scientists to observe all the energy levels of a variety of different atoms and molecules simultaneously.
  • High resolution or precision allows scientists to separate and identify signals that are very brief or close together, such as individual rotations out of hundreds of thousands in a water molecule. The resolution can be tweaked to reach below the limit set by the thermal motion of gaseous atoms or molecules at room temperature.
  • High sensitivity--currently 1 molecule out of 100 million--enables the detection of trace amounts of chemicals or weak signals. With additional work, the JILA team foresees building a portable tool providing detection capability at the 1 part per billion level. Such a device might be used, for example, to analyze a patient’s breath to monitor diseases such as renal failure and cystic fibrosis.
  • A fast data-acquisition time of about 1 millisecond per 15 nm of bandwidth enables scientists to observe what happens under changing environmental conditions, and to study molecular vibrations, chemical reactions and other dynamics.

By comparison, conventional cavity ring-down spectroscopy offers comparable sensitivity but a narrow bandwidth of about 1 nanometer. A more sensitive "optical nose" technique developed at NIST can identify one molecule among 1 trillion others, but can analyze only one frequency of light at a time. Other methods, such as Fourier transform infrared spectroscopy, provide large bandwidths and high speed but are not sensitive enough to detect trace gases.

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

More articles from Physics and Astronomy:

nachricht Light-emitting bubbles captured in the wild
28.02.2017 | Georg-August-Universität Göttingen

nachricht Scientists reach back in time to discover some of the most power-packed galaxies
28.02.2017 | Clemson University

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: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New technology offers fast peptide synthesis

28.02.2017 | Life Sciences

WSU research advances energy savings for oil, gas industries

28.02.2017 | Power and Electrical Engineering

Who can find the fish that makes the best sound?

28.02.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>