It could identify elements in one laser pulse

May 22, 2007 09:42 GMT  ·  By
Lawrence Livermore National Laboratory uses the Ultra Short Pulse Laser to create stellar conditions in the laboratory
   Lawrence Livermore National Laboratory uses the Ultra Short Pulse Laser to create stellar conditions in the laboratory

A team of physicists and engineers are working on a new laser-like X-ray source that will be powerful enough to effectively take snapshots of the atomic world, which moves at extremely high speeds. The research is funded by the US Department of Defense and aims to improve attosecond sources and exploit the technology breakthrough for applications.

Zenghu Chang, Kansas State University professor of physics and his team, think their efforts will pay off as the new attosecond technology may have valuable practical applications, like identifying elements in one laser pulse.

The research receives $1.25 million per year for three years with a possible two-year extension and will create a device capable of producing a laser pulse that could be beamed into a suspicious package, for example, to quickly determine if it did actually contain dangerous chemicals.

The job of identifying the basic constitutive elements of various materials can be carried using a special kind of X-ray, called attosecond pulses. These are extremely fast flashes of light, similar to a camera flash.

"Just like each person has his or her unique fingerprints, molecules can be identified by their unique features too," Chang said. "As an example, different molecules absorb light differently. That is why we see things with different colors. We can tell which one is made of gold and which one is made of silver just by looking at their colors.

"This is very similar to taking pictures of a moving body with a camera," he said. "One has to reduce the exposure time using the shutter of the camera for a fast-moving object otherwise the image is blurred."

This research in attoseconds focuses on developing the technique to control the phase of a laser pulse and then amplify it.

Many other practical applications could derive from this new technique. For example, high-power laser could be improved, since they could become much more precise with the help of the short pulses, which could permanently remove the possibility of cutting too much useful material due to its extra heat.