A light-driven energy trap similar to tractor beams used to capture spaceships in science fiction movies such as Star Trek and Star Wars has been developed by researchers in South Australia. The discovery is opening the way for new quantum experiments that may lead to new secure communications or advanced sensing technologies.

University of Adelaide researchers have created the infrared tractor beam – or light-driven energy trap – for atoms. But rather than sucking spaceships into a space station, their tractor beam pulls atoms into a microscopic hole at the centre of a special optical fibre.

Published in the journal Physical Review Applied, the researchers from the University’s Institute for Photonics and Advanced Sensing (IPAS) say this is the first time that scientists have been able to demonstrate a highly efficient ‘waveguide trap’.

The tractor beam works by the infrared light interacting with the atoms to create a change in energy that drives the atoms to the most intense part of the light beam.
PhD student Ashby Hilton developed the technology and said that although tractor beams in movies like Star Trek and Star Wars are green or blue, in this case the trap is made of invisible infrared light.

“The beam grabs hold of atoms that are floating in a chamber that is almost completely emptied of gas – a little sample of outer space on Earth,” he said. “Every atom that enters the tractor beam is pulled into the fibre – there is no escape.”

Once sucked into the interior of the optical fibre the atoms can be held for long periods of time.

The researchers are now moving onto the next stage in which the tractor beam is formed from a hollow cone of light rather than a solid beam of light. In this new configuration the atoms will be held at the centre of the light cone where it is perfectly dark.