Molecules Have Been Built Using a Laser Beam for the First Time

photo credit: Short laser pulses were used to create bonds between molecules, as illustrated here. Lightspring/Shutterstock

It’s official: Star Trek-style replicators are on the way. Well, sort of.

Assembly lines for specific molecules could be a thing of the future, thanks to a recent breakthrough in atomic bonding published in the journal Physical Review Letters. A team of scientists has found a way of using laser beams to control the path of chemical processes, possibly ushering in a new age of photochemistry.

Using light to control atomic bonding – known as coherent control – is not new; for decades, laser pulses have been successfully used to break bonds, but the reverse had proved difficult. Now a team of researchers from Israel's Hebrew University, the Technion-Israel Institute of Technology and the University of Kassel in Germany has demonstrated this process in action.

Very short pulses of light were shot at a group of magnesium atoms, causing some magnesium dimer Mg2 to form, two molecules of magnesium that are linked together. Adjusting the pulse shape, the team found they could increase the number of molecules that formed. What does this mean? Well, in principle, lasers could ultimately be used to "slice and weld molecular pieces into a desired end product," reported APS Physics.

One problem that had plagued researchers before is that it was hard to detect the bond creation in action and prove that it was not the result of random processes. To solve this problem, the team fired the lasers at just a small number of atoms in the gas for a millionth of a billionth of a second – known as a femtosecond.

“The energy absorbed from the pulse leads to a rearrangement of the atoms' electrons, resulting in a chemical bond,” lead researcher Christiane Koch told Chemistry World. She noted that the team had had difficulty getting funding, as it was unclear whether the process could work until now. “We hope that these accomplishments will motivate other groups to look again into the coherent control of chemical reactions and thus revive the field,” she added.

More research will be needed before we can truly herald the creation of Star Trek replicators. But it’s a start, at least.