Optical Antenna Allows In-Flight Communication Between Drones Using UV Light

New antenna design captures and amplifies UV signals over a wide area, maintaining secure links between fast-moving drones and other vehicles

Researchers have developed a new optical antenna for wireless ultraviolet (UV) communication that captures and amplifies signals from a broad area. The antenna could help keep multiple moving targets — like swarms of flying drones, convoys of vehicles or naval fleets — connected, even in dynamic environments.

When it comes to keeping groups of vehicles or drones connected, using light for communication instead of radio waves offers better security and immunity to radio interference. However, traditional optical links based on lasers require precise alignment, and even small movements can break the connection.

“UV communication is more flexible because it doesn’t require perfect alignment and works across varied conditions,” said research team leader Shiming Gao from Zhejiang University in China. “However, UV signals typically weaken quickly over distance. Our new antenna solves this challenge by boosting the received signal, creating a simpler and more reliable way for moving systems to stay connected.”

In the Optica Publishing Group journal Optics Letters, the researchers describe their new antenna, which can receive UV signals from 360 degrees horizontally within a wide 114-degree vertical viewing window. In an initial demonstration, they used the antenna to send a live still image from one flying drone to another.

“Our system enables multiple moving targets to stay tightly linked even if standard radio waves are jammed, hacked or unavailable,” said Gao. “This could be useful for a swarm of drones being used in a large wildfire where smoke and damaged infrastructure disrupt traditional communications. The drones could send real-time thermal imagery of the fire front to responders on the ground, improving situational awareness and safety.”

Keeping moving objects connected
For UV drone-to-drone communication, one drone transmits digital data by converting it into pulses of ultraviolet light, while the other uses a sensitive detector to capture the signals and convert them back into electrical form to reconstruct the original information.

The new work was motivated by the fact that UV signals weaken rapidly as they travel, leading the researchers to design a specialized optical receiving antenna. To determine the best antenna design for real‑world drone operations, they developed a computational model simulating how UV light travels through the air. The model tracked the paths of more than 100 million photons as they scattered, allowing the researchers to compare how well the system worked with and without the antenna.

This work led the researchers to a final antenna design that was based on a curved shape known as a 2D compound parabolic concentrator. This shape was tilted at a specific angle and revolved 360 degrees around a central axis to form a ring. Once the scattered UV light enters this ring, highly polished, mirrored surfaces on the top and bottom inside the antenna bounce and funnel those weak light rays, concentrating them downward directly into the UV light sensor.

“Previous omnidirectional antenna designs could detect signals in all directions but struggled to amplify horizontal signals, while other approaches delivered strong signal gain at those angles but lost the ability to capture signals from all directions simultaneously,” said Gao. “Our new device overcomes both of these past limitations, allowing drones to maintain a stable UV communication link even while moving around.”

In-flight demonstration
After confirming that the antenna could catch light signals from different angles and at distances up to 50 meters away, and maintain clear data waveforms at 30 meters, the researchers tested it on flying drones. They mounted a transmitter and receiver onto two drones that were flown outdoors about 6 meters apart. The invisible UV light link was then used to send a live digital still picture from one drone to the other at 9.6 kbps, a speed similar to early internet modems.

“The drone received the data and reproduced the picture with zero errors, proving that the system works incredibly well in real-world flight,” said Gao. “In the future, drones will likely serve as a flexible intermediate layer in future space-air-ground communication networks, helping extend and stabilize connectivity between satellites, aircraft and terrestrial systems. Our technology could help make this network possible by enabling these drones to maintain stable, reliable communication links.”

The researchers are now working to scale up their approach by using the antenna to connect an entire swarm or array of drones rather than just a single pair. They are also focused on significantly boosting the communication speed.

They also note that before commercialization, data rate and range must be improved through better transmitters and receivers; the system must be optimized with lightweight, compact power and control electronics; and it must undergo extensive real-world testing across diverse conditions to ensure reliability and safety.

About Optica Publishing Group
Optica Publishing Group is a division of the society, Optica, Advancing Optics and Photonics Worldwide. It publishes the largest collection of peer-reviewed and most-cited content in optics and photonics, including 19 prestigious journals, the society’s flagship member magazine, and papers and videos from over 1200 conferences. With over 520,000 journal articles, conference papers and videos to search, discover and access, its publications portfolio represents the full range of research in the field from around the globe.

About Optics Letters
Optics Letters offers rapid dissemination of new results in all areas of optical science with short, original, peer-reviewed communications. Optics Letters accepts papers that are noteworthy to a substantial part of the optics community. Published by Optica Publishing Group and led by Editor-in-Chief Carsten Rockstuhl, Karlsruher Institut für Technologie, Germany. For more information, visit https://opg.optica.org/ol/home.cfm