News in Science

Atom laser to keep spacecraft on track

A laser beam that emits a continuous stream of atoms may one day help ultra-precise navigation of space craft, say Australian experts.

Physicists Dr Nick Robins and colleagues from the Australian National University in Canberra report their progress on developing the first gyroscope of its kind, in the journal Nature Physics.

While atom lasers have been made before, research team member Associate Professor John Closesays the team has overcome a major barrier to developing a laser that pumps atoms continuously.

"It carries the promise of measuring at enormously increased precision," he says.

On-board gyroscopes are often used as part of a navigation system that can help determine location by keeping a record of in direction have been made since a particular starting point.

"There are many reasons why you would want a local measurement of what you're doing," says Close.

He says one application for this could be in a space craft that is too far away from earth to use a global positioning system.

Another application could be in a military submarine that doesn't want to give away its precise location.

Matter waves

Current gyroscopes often use light lasers to precisely measure rotation.

But Close says that atom lasers could provide much more accurate measurements by using "matter waves".

They plan to build two gyroscopes, which will be identical except that one will be made with a light laser and the other with an atom laser.

They will then test their precision in measuring the rotation of a range of objects.

Close says models predict that the atom laser will be 11 orders of magnitude more sensitive, offering 100 billion times more precise measurements.

This degree of precision could make a huge difference when it comes to navigating over the huge distances of space where small errors can have huge consequences, he says.

Other uses

Such a gyroscope could also be used to measure irregularities in the earth's rotation, says Close.

He says a pumped atom laser could also help measure changes in gravitational and magnetic fields - useful in remote sensing for mining for oil or iron ore.

And it could also be used to etch smaller circuits onto nanoscale devices.

Close says advances in measurement have been responsible for major changes in our society.

For example, Copernicus' measurement of the movement of planets with a telescope shifted our view of our location in the universe, he says.

And the measurement of longitude essential in modern navigation was only made possible by the invention of precise wind-up clocks.

The pumped atom laser research was funded by the Australian Research Council.