Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ultrafast laser technique developed to observe electron action

13.05.2014

University of Central Florida physicist Zenghu Chang has done it again. For a third time this year, his research group has published an article in a Nature journal.

This time, Chang and his team have developed a new ultrafast light source for observing electron motion in molecules – made up of nuclei and electrons – at the point before the nuclei start to move. By being able to observe what actually happens, scientists can begin to understand how an electron interacts with other electrons, which may help improve the efficiency of solar cells.


This is Zheng Chang in his lab at UCF.

Credit: UCF

"The charge migration that theorists have been predicting since 1999 happens so quickly we haven't been able to observe it yet," Chang said. "It's very exciting, because we have found a new way to build light sources that may allow us to see it in the future."

Being able to see this superfast interaction between electrons gives scientists another tool to unlock the rules that govern the quantum-mechanics world – a world where microscopic objects don't obey the laws of physics we have come to rely on for understanding in the macro world.

So how did Chang and his team manage to develop the new light source? The team borrowed an idea from Chang's earlier innovative work in the area of ultrafast lasers.

"We control the below-threshold harmonic light emission by using electromagnetic fields with time-dependent ellipticity, like we have done to the above-threshold high-order harmonics," said Chang referring to the creation of a 67-attosecond pulse of extreme ultraviolet light, which earned him international recognition. "We thought: Could we use the same gating fields to show the dependence of the below-threshold harmonic intensity on the carrier-envelope phase of the driving laser? It took us some time to find the right experimental parameters, but the answer is yes."

The result of his study "Coherent phase-matched VUV generation by field-controlled bound states" appears this week in Nature Photonics.

Chang has been studying light and ultrafast lasers his entire career. This past year UCF established the Institute for the Frontier of Attosecond Science and Technology (FAST). The institute is a collaboration between experts and students in UCF's College of Optics and Photonics (CREOL) and the College of Sciences' physics department to focus on this field of science.

Co-authors include: Michael Chini, Xiaowei Wang, Yan Cheng, Yi Wu and Eric Cunningham from UCF's FAST; Peng-Cheng Li, John Heslar and Shih-I Chu from the Center for Quantum Science and Engineering and the Department of Physics at the National Taiwan University; He Wang from the Materials Sciences Division at the Lawrence Berkeley National Laboratory, and Dmitry A. Telnov from the Department of Physics at St. Petersburg State University in Russia.

"It was truly a collaborative effort," Chang said. "And there are certainly commercial applications. We're talking about cutting-edge lasers with potential application in electronics, navigation, communications and medicine."

Chang said he is excited about the new work because he hopes it will help lead to bigger and greater discoveries.

"My dream is to discover new physics that has not been predicted at this time," Chang said. "Until there was a microscope, we had no idea how complicated, how amazing cells were. What we are creating now are tools for magnifying time in order to discover what we have not even imagined yet. That's what I see for the future of our field."

###

The Defense Advanced Research Projects Agency, National Science Foundation, U.S. Department of Energy, National Science Council of Taiwan and National Taiwan University funded the research.

America's Partnership University: The University of Central Florida, the nation's second-largest university with nearly 60,000 students, has grown in size, quality, diversity and reputation in its first 50 years. Today, the university offers more than 200 degree programs at its main campus in Orlando and more than a dozen other locations. UCF is an economic engine attracting and supporting industries vital to the region's future while providing students with real-world experiences that help them succeed after graduation. For more information, visit http://today.ucf.edu.

Zenaida Kotala | Eurek Alert!

Further reports about: Photonics Physics Quantum UCF Ultrafast electrons lasers nuclei physics technique

More articles from Physics and Astronomy:

nachricht LIGO confirms RIT's breakthrough prediction of gravitational waves
12.02.2016 | Rochester Institute of Technology

nachricht Milestone in physics: gravitational waves detected with the laser system from LZH
12.02.2016 | Laser Zentrum Hannover e.V.

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: Production of an AIDS vaccine in algae

Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.

The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Symposium on Climate Change Adaptation in Africa 2016

12.02.2016 | Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

 
Latest News

LIGO confirms RIT's breakthrough prediction of gravitational waves

12.02.2016 | Physics and Astronomy

Gene switch may repair DNA and prevent cancer

12.02.2016 | Life Sciences

Using 'Pacemakers' in spinal cord injuries

12.02.2016 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>