Laser Tractor Bean: Star Trek in Real Life

laser tractor beam

Time for an exciting Star Trek related news item! Physicists have built a laser tractor beam that can repel and attract objects. The tractor beam works by using a hollow laser beam that’s bright around the edges to create hot-spots on the particles being moved. Does this mean we will soon have a fleet of star ships equipped with laser tractor beams any time soon?

The tractor beam is a staple of science fiction movies! The ability to move particles without a physical tether is a nice feature to have on any space ship you happen to get your hands on. This idea has been around in science fiction for a long time capturing the imaginations of physicists in the real world to figure out the physics behind the technology. There have been some progress lately using water, but a classical tractor beams remain elusive. Until now, when physicists at Australian National University in Canberra have constructed a working laser tractor beam.

Laser Tractor Beam – Star Trek is Real!

This tractor beam uses a hollow laser tractor beam to move small gold-coated hollow glass particles by creating hot-spots on its surface.

The tractor beam has managed to move particles one fifth of a millimeter big, a distance of 20 centimeters or about 8 inches. This might not sound like very far, but it’s still a 100 times further than people have managed in the past.

The beam works by heating up spots on particles which makes it move by the air around it being repelled. A particle is fixed in the hollow center of the laser beam. This laser hits the surface of the particle creating hot-spots. When theses hot-spots contact air particle, they shoot way from the hot-spots propelling the particle in the opposite direction. To control where these hot-spots appear researchers manipulate the laser beam’s polarization. This enables fine movement control of the particle with the laser tractor beam.

Although not ready for science fiction physics these laser tractor beams are usable today! They can potentially move delicate or dangerous particles for sampling. If the technique is scalable it might be able to work over longer distance with greater force moving bigger things than particles or small glass beads. Moving spaceships with the laser tractor beam still seem unlikely, but the science behind this laser works as a proof of concept and might be able to move heavier objects in the future. Besides we have more problems with the physics behind building spaceships than we have with moving them at least now.