Featured Research

from universities, journals, and other organizations

Towards perfect control of light waves

Date:
January 13, 2014
Source:
Technische Universitaet Muenchen
Summary:
Scientists have constructed a detector, which provides a detailed picture of the waveforms of femtosecond laser pulses (1 fs = 10-15 seconds). Knowledge of the exact waveform of these pulses enables scientists to reproducibly generate light flashes that are a thousand times shorter -- lasting only for attoseconds -- and can be used to study ultrafast processes at the molecular and atomic levels.

Tim Paasch-Colberg with the Femtosecond-Laser at the Laboratory for Attosecond Physics.
Credit: Thorsten Naeser / MPQ

A team at the Laboratory for Attosecond Physics (LAP) in Garching (Germany) has constructed a detector, which provides a detailed picture of the waveforms of femtosecond laser pulses (1 fs = 10-15 seconds). Knowledge of the exact waveform of these pulses enables scientists to reproducibly generate light flashes that are a thousand times shorter -- lasting only for attoseconds -- and can be used to study ultrafast processes at the molecular and atomic levels.

Modern mode-locked lasers are capable of producing extremely short light flashes that last for only a few femtoseconds. In one femtosecond light, which rushes from the Earth to the Moon in just one second, advances only three ten-thousandths of a millimeter. Such short pulses consist of only one or two oscillations of the electromagnetic field, which are preceded and followed by waves of lower amplitude that are rapidly attenuated. To be utilized in an optimal manner to probe ultrashort processes that occur at the level of molecules and atoms it is important to know the precise form of the high-amplitude oscillations.

A team at the Laboratory for Attosecond Physics at the Max Planck Institute for Quantum Optics (MPQ) including scientists from Technische Universitaet Muenchen (TUM), Ludwig Maximilians-Universitaet Muenchen (LMU) and further co-operation partners has now developed a glass-based detector that allows to accurately determine the form of the light waves that make up an individual femtosecond pulse.

In the course of experiments performed over the past several years, physicists in the group led by Professor Ferenc Krausz (MPQ/LMU) and Professor Reinhard Kienberger (TUM) have learned that, when pulsed high-intensity laser light impinges on glass, it induces measurable amounts of electric current in the material. Krausz and his colleagues have now found that the direction of flow of the current generated by an incident femtosecond pulse is sensitively dependent on the exact form of its wave packet.

In order to calibrate the new glass detector, the researchers coupled their system with a conventional instrument used to measure waveforms of light. Since the energy associated with the laser pulse is sufficient to liberate bound electrons from atoms of a noble gas such as xenon, the "classical" detector measures the currents caused by the motions of these free electrons. But there is a catch -- the measurements must be done in a high vacuum.

By comparing the currents induced in the new solid-state detector with the data obtained using the conventional apparatus, the team was able to characterize the performance of their new glass-based set-up, so that it can now be used as a reliable phase detector for few-cycle femtosecond laser pulses. The new instrument enormously simplifies measurements in the domain of ultrafast physical processes, because one can dispense with the use of cumbersome vacuum chambers. Moreover, in its practical application the technique is much more straightforward than the methods available for the mapping of waveforms hitherto.

If the precise waveform of the femtosecond laser pulse is known, it becomes possible to reproducibly generate stable trains of ultrashort attosecond light flashes, each one a thousand times shorter than the pulse used to induce them. The composition of the attosecond flashes is in turn highly dependent on the exact shape of the femtosecond pulses. Attosecond flashes can be used to "photograph" the motions of electrons in atoms or molecules. In order to obtain high-resolution images, the length of the flashes must be tuned to take account of the material one wants to investigate.

Highly sensitive and reliable measurements of physical processes at the level of the microcosmos with the aid of single attosecond light flashes of known shape should become easier to perform because, thanks to the new glass-based phase detector, the source of the energy to drive them -- the waveform of the laser pulses -- can now be controlled much more easily than before.

The research was funded by the European Research Council (ERC), the Marie Curie International Incoming Fellowship Program of the European Union, the German Research Foundation via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP), the Swiss National Science Foundation and the Alexander von Humboldt Foundation.


Story Source:

The above story is based on materials provided by Technische Universitaet Muenchen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tim Paasch-Colberg, Agustin Schiffrin, Nicholas Karpowicz, Stanislav Kruchinin, Özge Sağlam, Sabine Keiber, Olga Razskazovskaya, Sascha Mühlbrandt, Ali Alnaser, Matthias Kübel, Vadym Apalkov, Daniel Gerster, Joachim Reichert, Tibor Wittmann, Johannes V. Barth, Mark I. Stockman, Ralph Ernstorfer, Vladislav S. Yakovlev, Reinhard Kienberger, Ferenc Krausz. Solid-state light-phase detector. Nature Photonics, 2014; DOI: 10.1038/nphoton.2013.348

Cite This Page:

Technische Universitaet Muenchen. "Towards perfect control of light waves." ScienceDaily. ScienceDaily, 13 January 2014. <www.sciencedaily.com/releases/2014/01/140113104839.htm>.
Technische Universitaet Muenchen. (2014, January 13). Towards perfect control of light waves. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2014/01/140113104839.htm
Technische Universitaet Muenchen. "Towards perfect control of light waves." ScienceDaily. www.sciencedaily.com/releases/2014/01/140113104839.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com
What Is Magic Leap, And Why Is It Worth $500M?

What Is Magic Leap, And Why Is It Worth $500M?

Newsy (Oct. 22, 2014) — Magic Leap isn't publicizing much more than a description of its product, but it’s been enough for Google and others to invest more than $500M. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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