A small hollow wire can produce a donut-shaped laser beam that can be used to levitate small objects or transmit information.
Traditional lasers typically produce a beam that appears as a single, small spot of light when it hits a surface. But for some new communication technologies that use light to transfer information, it may be better to use lasers, which produce a hollow beam, like a straw, that appears as a halo of light when it hits a surface.
Such a hollow laser…
Source: www.newscientist.com