Featured Research

from universities, journals, and other organizations

A sharp eye for molecular fingerprints: Broad absorption spectra recorded on microsecond scale with two laser frequency combs

Date:
February 28, 2014
Source:
Max Planck Institute of Quantum Optics
Summary:
Scientists have developed a new method of real-time identification and quantification of molecular species. How to retrieve greenhouse gas concentrations in earth atmosphere or to test fundamental laws of quantum mechanics? By measuring the spectrum of light interacting with matter, i.e. measuring the intensity of light transmitted through a medium as a function of its color, it can be done. Each molecule leaves its fingerprint: characteristic absorptions, which make it possible to unambiguously identify it and measure its concentration.

Portion of a dual-comb real-time absorption spectrum of acetylene in the near-infrared region. While the spectrum without the adaptive sampling (blind sampling) is strongly distorted, the adaptive spectrum accurately reveals the molecular profiles.
Credit: MPQ, Laser Spectroscopy Division

A team of scientists working with Dr. Nathalie Picqué and Prof. Theodor W. Hänsch at the Laser Spectroscopy Division of the Max Planck Institute of Quantum Optics (Garching), in a collaboration with the Ludwig-Maximilians-Universität Munich and the Institut des Sciences Moléculaires d'Orsay (France) now reports on a new method of real-time identification and quantification of molecular species.

How to retrieve greenhouse gas concentrations in earth atmosphere or to test fundamental laws of quantum mechanics? By measuring the spectrum of light interacting with matter, i.e. measuring the intensity of light transmitted through a medium as a function of its color, it can be done. Each molecule leaves its fingerprint: characteristic absorptions, which make it possible to unambiguously identify it and measure its concentration. Recording an absorption spectrum that spans a broad spectral bandwidth in real-time (<1 millisecond) is an appealing quest to scientists working in this field: hundreds of molecules may then be simultaneously tracked. Research in chemical kinetics or homeland security gas detection would e.g. benefit from such capabilities.

In recent years, a new spectroscopic technique, called dual-comb spectroscopy, has demonstrated a very exciting potential for ultra-rapid recording of complex molecular spectra. Compared to the state-of-the-art instrumentation, Fourier transform spectroscopy, recording times could be shortened from seconds to microseconds. Dual-comb spectroscopy without moving parts harnesses two laser frequency combs, coherent sources that emit a regular train of ultrashort pulses, to perform interferometric measurements.

However, the technique of dual-comb spectroscopy has not realized its full potential yet, mostly because it is difficult to synchronize the two comb lasers within the required precision. The MPQ scientists have now developed a new approach to adaptive sampling, so that they are able to use unstabilized free-running femtosecond lasers without sacrificing performance. By generating proper clock signals, they compensate for laser short-term instabilities by electronic signal processing only.

This demonstrated possibility of using femtosecond lasers without any sophisticated stabilization scheme considerably eases the implementation of a dual-comb spectrometer. "It should facilitate applications to real-time sensing," comments Takuro Ideguchi, who just completed his doctoral dissertation, partly based on this experiment. "Dual-comb spectroscopy holds much promise for new approaches to molecular physics and our scheme of adaptive sampling is a key to their efficient implementation. Enhanced sensitivity for weak concentrations is within reach with the development of mid-infrared frequency combs, while nonlinear dual-comb spectroscopy provides intriguing prospects for applications ranging from bio-imaging to precision spectroscopy," Takuro Ideguchi adds.


Story Source:

The above story is based on materials provided by Max Planck Institute of Quantum Optics. Note: Materials may be edited for content and length.


Journal Reference:

  1. Takuro Ideguchi, Antonin Poisson, Guy Guelachvili, Nathalie Picqué, Theodor W. Hänsch. Adaptive real-time dual-comb spectroscopy. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4375

Cite This Page:

Max Planck Institute of Quantum Optics. "A sharp eye for molecular fingerprints: Broad absorption spectra recorded on microsecond scale with two laser frequency combs." ScienceDaily. ScienceDaily, 28 February 2014. <www.sciencedaily.com/releases/2014/02/140228080649.htm>.
Max Planck Institute of Quantum Optics. (2014, February 28). A sharp eye for molecular fingerprints: Broad absorption spectra recorded on microsecond scale with two laser frequency combs. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2014/02/140228080649.htm
Max Planck Institute of Quantum Optics. "A sharp eye for molecular fingerprints: Broad absorption spectra recorded on microsecond scale with two laser frequency combs." ScienceDaily. www.sciencedaily.com/releases/2014/02/140228080649.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Air Force: $4.2B Saved from Grounding A-10s

Air Force: $4.2B Saved from Grounding A-10s

AP (Apr. 23, 2014) — Speaking about the future of the United States Air Force, Chief of Staff Gen. Mark Welsh says the choice to divest the A-10 fleet was logical and least impactful. (April 23) Video provided by AP
Powered by NewsLook.com
Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) — South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) — The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) — Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins