Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Standoff sensing enters new realm with dual-laser technique

23.03.2012
Identifying chemicals from a distance could take a step forward with the introduction of a two-laser system being developed at the Department of Energy's Oak Ridge National Laboratory.

In a paper published in the Journal of Physics D: Applied Physics, Ali Passian and colleagues present a technique that uses a quantum cascade laser to "pump," or strike, a target, and another laser to monitor the material's response as a result of temperature-induced changes. That information allows for the rapid identification of chemicals and biological agents.

"With two lasers, one serves as the pump and the other is the probe," said Passian, a member of ORNL's Measurement Science and Systems Engineering Division. "The novel aspect to our approach is that the second laser extracts information and allows us to do this without resorting to a weak return signal.

"The use of a second laser provides a robust and stable readout approach independent of the pump laser settings."

While this approach is similar to radar and lidar sensing techniques in that it uses a return signal to carry information of the molecules to be detected, it differs in a number of ways.

"First is the use of photothermal spectroscopy configuration where the pump and probe beams are nearly parallel," Passian said. "We use probe beam reflectometry as the return signal in standoff applications, thereby minimizing the need for wavelength-dependent expensive infrared components such as cameras, telescopes and detectors."

This work represents a proof of principle success that Passian and co-author Rubye Farahi said could lead to advances in standoff detectors with potential applications in quality control, forensics, airport security, medicine and the military. In their paper, the researchers also noted that measurements obtained using their technique may set the stage for hyperspectral imaging.

"This would allow us to effectively take slices of chemical images and gain resolution down to individual pixels," said Passian, who added that this observation is based on cell-by-cell measurements obtained with their variation of photothermal spectroscopy. Hyperspectral imaging provides not only high-resolution chemical information, but topographical information as well.

Other authors are ORNL's Laurene Tetard, a Wigner Fellow, and Thomas Thundat of the University of Alberta. Funding for this research was provided by ORNL's Laboratory Directed Research and Development program.

UT-Battelle manages ORNL for the Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/

Ron Walli | EurekAlert!
Further information:
http://science.energy.gov/
http://www.ornl.gov

More articles from Process Engineering:

nachricht Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>