Laser scientists build tractor beam

Laser physicists in Australia have built a tractor beam that can repel and attract objects, using a hollow laser beam that is bright around the edges and dark in its centre, the Australian National University (ANU) announced on Monday.

It is the first long-distance optical tractor beam and moved particles one-fifth of a millimetre in diameter a distance of up to 20 cm, around 100 times further than previous experiments, Xinhua reported. The new technique could be used, for example, in controlling atmospheric pollution or for the retrieval of tiny, delicate or dangerous particles for sampling. — IANS