Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Three-dimensional view helps laser in building new molecules

International team of scientists develops new feedback method for optimizing the laser pulse shapes used in the control of chemical reactions

In many ways, traditional chemical synthesis is similar to cooking. To alter the final product, you can change the ingredients or their ratio, change the method of mixing ingredients, or change the temperature or pressure of the environment of the ingredients.

Illustration of driving chemical reactions in molecules with laser pulses (Graphic: MPQ, Laboratory of Attosecond Physics)

Like an accomplished chef, chemists have become very skilled at the manipulation of these parameters to produce many of the products that make our lives better.

But there are some things that resist these methods. As a result, researchers are continually looking for new techniques to apply. In particular, laser-based chemistry has been a goal for researchers since the invention of the laser in the 1960s. Applying a laser pulse of the correct color and duration to a molecule could, in principle, inject just the right amount of energy to modify a specific chemical bond and change the molecule into a more desirable configuration. In this sense, the laser can be thought of as a new type of reagent that drives a chemical reaction.

In practice, even a single molecule is a complicated system and finding the correct laser pulse characteristics to influence molecules is difficult. In addition, sophisticated laser pulse shaping devices can produce a nearly infinite number of pulse shapes, making a systematic search for the correct laser-molecule solution daunting.

A proven method for approaching this problem is to use experimental feedback to guide an adaptive search of the possible laser pulses. As in natural selection, laser pulses that provide a better outcome are given an increased chance to survive and have their characteristics contribute to the tailored pulse that ultimately produces the desired outcome. Such a method, however, is only as good as the feedback that drives it.

In an article published this week in the journal Nature Communications, researchers from Augustana College (SD) and Kansas State University (KSU) in the United States and from the Max Planck Institute for Quantum Optics (MPQ) and the Ludwig Maximilian University (LMU) in Munich, Germany, have reported an improved feedback technique. By imaging the dissociating molecule in three dimensions, a laser pulse can be optimized to drive the molecule to a very specific final state. This image-based technique can complement feedback methods that depend on optical spectroscopy. Furthermore, the researchers were able to use the dissociation images to guide theoretical work that revealed how the laser pulse was able to control the molecule, in this case driving acetylene ions from the normal HCCH configuration to the unusual HHCC configuration.

Building on the initial work done at MPQ, Augustana students developed a method for converting the image into feedback quickly enough to be useful in the experiment. They then developed a system of computer control linking the entire experiment as well as refining image-analysis techniques to evaluate the experimental data. Once this was accomplished, the experiment was conducted at the J.R. Macdonald Laboratory. Initial results stimulated the theoretical work performed at LMU to clarify the control mechanism.

“The experiment shows that improved feedback, provided by multi-dimensional imaging, enhances both our abilities to control chemical reactions and the physical insight that can be gained”, said Matthias Kling, research group leader at MPQ and assistant professor at KSU at the time the studies were conducted. “The new methodology provides new possibilities for the control of more complex systems including larger molecules, clusters, and nanoparticles. Multi-dimensional data provide stricter limitations for theory and will help to improve our models”, explains Regina de Vivie-Riedle, professor at LMU and leader of the group that performed the theory.

Augustana College personnel and equipment were funded by National Science Foundation Grant No. 0969687 and National Science Foundation/EPSCoR Grant No. 0903804. KSU operations and personnel were supported by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. Additional funding was provided by support by the German Research Foundation via the Cluster of Excellence: “Munich Center for Advanced Photonics (MAP)” and via the DFG grants Kl-1439/2 and Kl-1439/3.

Original publication:
E. Wells, C.E. Rallis, M. Zohrabi, R. Siemering, Bethany Jochim, P.R. Andrews, U. Ablikim, B. Gaire, S. De, K.D. Carnes, B. Bergues, R. de Vivie-Riedle, M.F. Kling, and I. Ben-Itzhak
Adaptive Strong-field Control of Chemical Dynamics Guided by Three-dimensional Momentum Imaging

Nature Communications 4:2895 DOI: 10.1038/ncomms3895 (2013).

Prof. Dr. Matthias Kling
Laboratoy of Attosecond Physics
Ludwig-Maximilians-Universität Munich,
Max-Planck-Institute of Quantum Optics
Hans-Kopfermann-Straße 1, Garching
Phone: +49 (0)89 / 32 905 -234
Prof. Dr. Regina de Vivie-Riedle
Ludwig-Maximilians-Universität Munich
Department Chemie
Butenandt-Str. 11, 81377 Munich
Phone: +49 (0)89 / 2180 - 77 533 / Fax -77 133
Prof. Eric Wells
Department of Physics
Augustana College
2001 S. Summit Ave
Sioux Falls, SD 57197, USA
Prof. Itzik Ben-Itzhak
J.R. Macdonald Laboratory
Physics Department
Kansas-State University
116 Cardwell Hall, Manhattan, KS 66506, USA

Dr. Olivia Meyer-Streng | Max-Planck-Institut
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>