Lasers smaller than a human hair emit doughnut-shaped light

Tiny, hollow wires can produce doughnut-shaped laser light that could be used to levitate small objects or transmit information.

Conventional lasers typically make beams that appear as a single, small point of light when they hit a surface. But for some novel communication technologies that use light to transfer information, it can be better to use lasers that produce hollow beams like a drinking straw, which appear as a ring of light when they hit a surface.

Such hollow laser…