Images posted on X showing various Russian fiber-optic drone systems.
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Last year, fiber-optic drones emerged as a game-changing technology in the Russia-Ukraine War. By transmitting data through fiber-optic cables, these drones are immune to the electronic warfare systems that both sides use to disrupt the control and navigation signals required by traditional drones. Despite their increased use, the effectiveness of fiber-optic drones has been limited by range, constrained by signal loss through the cable and the heavy weight of the spool. However, a Kremlin-affiliated milblogger recently posted on Telegram that the Russian military has addressed this issue with the introduction of new fiber-optic repeater drones.
Fiber-Optic Repeater Drones
Although only limited information has been released, the concept of fiber-optic repeater drones is straightforward. The system consists of a larger repeater drone connected to several strike drones, all controlled through fiber-optic cables. A primary cable runs from the operator to the repeater drone, where the signal is boosted and then forwarded to the appropriate strike drone. The Russian milblogger claims that this arrangement allows the strike drones to reach targets up to 50 to 60 kilometers away, since the cable load is shared between the repeater and the strike drones. In theory, multiple repeaters could potentially be used to increase this range.
Image posted on social media showing a field in Ukraine covered with fiber-optic threads from drone usage.
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When deployed, the drones fly together so that the strike drones’ fiber-optic cables remain mostly spooled. Upon reaching a designated location, the repeater drone stops while the strike drones continue forward, unspooling their cables as they advance. The strike drones then find and engage their targets. The milblogger and subsequent reports on Ukrainian and Russian media suggest that the repeater drone can then return to the operator, retracting its fiber-optic cable for reuse.
Battlefield Implications of Fiber-Optic Repeater Drones
Over the past year, fiber-optic drones have become a central element of the Russian drone arsenal. When first introduced on the battlefield, they were used primarily to destroy high-value targets, particularly Ukrainian counter-drone systems. By neutralizing those systems, Russia was able to operate its other drones with relative impunity. As these drones became more widely available, Russia increasingly used them to strike key Ukrainian targets, especially in areas affected by jamming. When paired with repeater drones to extend range, fiber-optic strike drones can reach deeper into Ukrainian territory, increasing the overall threat to Ukrainian forces.
Image capture from video posted on social media reportedly showing the video from a Russian fiber-optic FPV drone as it strikes a Ukrainian pick-up vehicle.
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Building on this capability, Russian forces have developed “kill zones” ahead of their frontlines by using a combination of fiber-optic and traditional drones. In particular, these zones have been established ahead of Russian lines in the Donetsk and Kharkiv Oblast. They complicate Ukrainian attempts to mount coordinated attacks, while also making resupply of units inside the zones far more difficult. The depth of these kill zones is limited by how far drones can operate before Ukrainian jamming degrades their effectiveness. The use of repeater drones extends that reach and can potentially double the depth.
The introduction of repeater drones also enhances Russia’s ability to strike rear-area infrastructure that supports frontline operations. Ukrainian officers report that Russian forces are systematically targeting logistics hubs, depots, roads, and evacuation routes in Donetsk Oblast to weaken the Ukrainian “fortress cities” in the region. With repeater drones extending operational range, these strikes can reach deeper into the Ukrainian near rear, disrupting supply and movement and giving Russian forces an operational advantage.
Potential Methods to Counter Fiber-Optic Repeater Drones
Throughout the war, Ukraine has been consistently successful in developing counter-drone measures in response to advances in Russian drone technology. Ukraine has already established a number of defense tactics against the fiber-optic strike drones. Their limited maneuverability and low flight altitude allows specialized counter-drone teams to shoot them with shotguns. Additionally, Ukraine has developed anti-drone netting that covers key logistics routes to prevent these drones from hitting vehicles.
Image capture from a video posted on social media reportedly showing a Ukrainian soldier using an automatic shotgun to shoot down a Russian fiber-optic drone.
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More sophisticated measures will likely soon be developed, especially targeting the repeater drone, since destroying a repeater would disable all connected strike drones. One vulnerability is the fiber-optic cable itself, which can produce a visible glint, particularly under certain lighting conditions or when covered with frost. By detecting these glints through visual observation, infrared imaging, or laser illumination, Ukraine could potentially locate and target the repeater drones.
Ukraine has shown a consistent ability to adapt to new Russian technologies and will eventually develop effective counters to fiber-optic repeater drones as well. They will also likely field their own versions of these systems, allowing them to strike deeper behind Russian lines. For now, however, the introduction of these drones provides Russia with an advantage by extending its reach and complicating Ukrainian operations.