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 July 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 July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) — 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) — Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) — Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) — Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
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