Blended lasers make a tasty tractor beam

摘要

At last we have a tractor beam that can move particles around, and can do the job in space as well as on Earth. Built with twin lasers, the device might not compare to anything out of Star Trek, but it has grabbed NASA's attention as it could one day prove useful for exploring other worlds. Lasers are a standard way to build optical "tweezers" that can pick up a microscopic object and put it down a short distance away. A more recent device is able to pull on particles, but it relies on sensitive temperature variations in the beam, making it hard to deploy in space.