Light usually travels straight, like a flashlight beam. But it can be twisted, like water in a funnel, creating a vortex in the beam. Such twisted light can carry more data: different vortices don't interfere with each other, just like different radio channels. The challenge was to make a source of such light small enough for a chip.

Engineers have built a laser smaller than a cubic micrometer — about the size of a grain of sand shrunk a thousand times. Inside, the light twists itself thanks to a special pattern of tiny holes. This pattern acts like a maze that guides light only along a spiral path. The laser turns on with just 0.74 microwatts of power — thousands of times less than a remote control's LED.

Such a vortex light source could be integrated directly into processors. Then computers could exchange data using light instead of electricity — faster and with less heat. A microlaser with a twisted beam is like a tiny fountain that, instead of a stream of water, emits a spiral flow of photons.