Here’s how to make fiber-optic cable out of thin air using a laser

Tubular laser beams can create fiber-optic cables made as thin as air, researchers report in a new study. Physics Review X.

Laser-heated air can efficiently illuminate signals without the need to lay down fiber-optic cables. These air-based “waves” may also provide pathways for ultrahigh-energy lasers, which do not propagate well through air itself, in previous attempts to build what was touted as a pathway to laser beam weapons.SN: 3/5/14).

The latest experiments, said scientist Howard Milchberg of the University of Maryland in College Park, the team shook the waves of previous attempts more than 60 times, extending the length of the waves to almost 50 meters.

The researchers ran the laser in the donut mode, where the beam is hollowed out along the length of the core, like a pile of luminous doughnuts. The beam creates a warm, tubular layer of air surrounded by cooler, denser air. It does something similar with a fiber-optic cable made of air: Instead of a transparent core covered in a plastic key that shines in a conventional optical fiber, dense air acts as the core, while hot air surrounds it as a barrier.

Milchberg says that elevating to a length of kilometers is primarily a matter of donut-style laser power boosting. “The only thing we don’t have is a kilometer” to safely fire the laser at a distance, he said. He may negotiate with one of the US national laboratories to find space for a longer version of the experiment.

Despite the potential military applications, Milchberg says he and his team are focusing more on scientific uses, such as developing scaling systems that unlock the chemical structure of materials, fire lasers at them and measure the light they emit. Air-based waveguides could send the emitted light back to systems located far away, not needing to be closer to the sample for analysis.