Here's how to make a fiber-optic cable out of air using a laser – Science News Magazine

Here's how to make a fiber-optic cable out of air using a laser – Science News Magazine

Support nonprofit journalism.
Specially tailored laser beams can create a channel in the air through which light can efficiently travel, creating something akin to a fiber optic cable made of air.
Михаил Руденко/iStock/Getty Images Plus

Tubular laser beams can create what amount to fiber-optic cables made of thin air, researchers report in a study to appear in Physical Review X.
Laser-heated air can efficiently transmit light signals without the need to lay fiber-optic cables. These air-based “waveguides” can also provide pathways for ultrahigh-energy lasers that don’t propagate well through air on their own, building on earlier efforts that have been touted as a route to laser beam weapons (SN: 3/5/14).
Headlines and summaries of the latest Science News articles, delivered to your email inbox every Thursday.
Thank you for signing up!
There was a problem signing you up.
The latest experiments, says physicist Howard Milchberg of the University of Maryland in College Park, beat out his team’s prior waveguide attempts by more than 60 times, extending the length of a waveguide to nearly 50 meters.
The researchers ran a laser in “doughnut mode,” where the beam has a hollowed-out core along its length, resembling a stack of luminous doughnuts. The beam creates a hot, tubular air layer wrapped around cooler, denser air. This creates something akin to a fiber-optic cable made of air: Instead of a transparent core covered in plastic cladding that guides light in conventional fiber optics, the dense air acts as the core, while the hot air around it serves as cladding.
Stepping up the waveguide length to kilometers, Milchberg says, is primarily a matter of boosting the doughnut-mode laser power. “The only issue is we don’t have a kilometer” to safely fire a laser that far, he says. It may take a deal with one of the U.S. national laboratories to find space to run a longer version of the experiment.
Despite the potential military applications, Milchberg says he and his team are focused more on scientific uses, such as extending the range of systems that reveal the chemical makeup of materials by firing lasers at them and measuring the light they give off. Air-based waveguides could send emitted light back to remotely located systems, instead of needing to get up close to analyze a sample.
Questions or comments on this article? E-mail us at
A. Goffin et al. Optical guiding in 50-meter-scale air waveguidesPhysical Review X, in press, 2022.
James Riordon is a freelance science writer who covers physics, math, astronomy and occasional lifestyle stories.
Our mission is to provide accurate, engaging news of science to the public. That mission has never been more important than it is today.
As a nonprofit news organization, we cannot do it without you.
Your support enables us to keep our content free and accessible to the next generation of scientists and engineers. Invest in quality science journalism by donating today.
Science News was founded in 1921 as an independent, nonprofit source of accurate information on the latest news of science, medicine and technology. Today, our mission remains the same: to empower people to evaluate the news and the world around them. It is published by the Society for Science, a nonprofit 501(c)(3) membership organization dedicated to public engagement in scientific research and education (EIN 53-0196483).
© Society for Science & the Public 2000–2023. All rights reserved.
Subscribers, enter your e-mail address for full access to the Science News archives and digital editions.
Not a subscriber?
Become one now.


Leave a Reply

Your email address will not be published. Required fields are marked *