Fiber optic unmanned aerial vehicle. According to foreign media reports, in recent regional conflicts, a fighter cut a thin line trailing from the tail of a flying drone, causing the drone to lose control and crash into the ground, resulting in an explosion. Why is there still such a drone dragging a long thin line at the tail in today's widely used wireless communication technology? In fact, this is not an ordinary connecting wire, but an optical fiber used for data transmission. This type of unmanned aerial vehicle with a "wired" design is precisely the fiber optic unmanned aerial vehicle that has frequently appeared in recent years. The emergence of fiber optic drones for transmitting signals through optical fibers is not accidental, but a product of the upgrading of attack and defense on modern battlefields. With the widespread application of radio frequency communication technology and unmanned technology, unmanned aerial vehicles have ushered in a "golden period" of development. At the same time, technologies such as electronic interference and signal hijacking have rapidly developed for traditional communication links. In strong electromagnetic interference environments, drones often face risks such as image interruption, GPS signal loss, and even control takeover, greatly reducing their combat effectiveness. How to ensure the safety of drones in strong electromagnetic interference environments has become a challenge for military technicians. In this context, fiber optic drones have emerged. Fiber optic, also known as optical fiber, is a flexible transparent fiber made of glass or plastic used to conduct light waves. Fiber optics have the characteristic of "total reflection of light", where optical signals undergo continuous reflection within the channel formed by the fiber core and cladding, enabling long-distance and low loss transmission. Fiber optic drones cleverly combine the characteristics of fiber optics with drones, solving many of the challenges faced by traditional drones on the battlefield. Fiber optic unmanned aerial vehicles consist of unmanned aerial vehicles, fiber optic cable barrels, and optoelectronic converters. The maximum flight altitude of a regular fiber optic drone is up to 5000 meters, and the flight distance is usually within 10 kilometers, which can be increased to 40 kilometers under specific conditions. The fastest flight speed is about 120 kilometers per hour, and the flight time is 10 to 49 minutes. It can carry 1 to 2 kilograms of explosives. After the fiber optic drone takes off, the fiber optic cables it carries are continuously released. The high-definition images captured by drones are transmitted back in the form of optical signals through optical fibers, converted by photoelectric converters, and then fed back to ground operators. The outstanding advantage of fiber optic drones with strong anti-interference ability lies in their high ability to resist electromagnetic interference and signal transmission in a sealed manner. Due to the use of optical fibers as transmission channels, fiber optic drones can be protected from various electronic interference threats. This means that fiber optic drones can approach high-value targets on the battlefield, such as command posts and anti-aircraft missile positions, for strikes. In contrast, traditional drones are more likely to be subject to electromagnetic interference or destruction by the enemy once they approach these important targets. According to relevant foreign data, fiber optic drones can survive for nearly 12 hours in strong electromagnetic interference environments, which is far less than that of ordinary drones. In addition, due to the propagation of optical signals in enclosed fiber optic channels, they will not be obstructed or intercepted, so fiber optic drones have strong communication and covert combat capabilities. On the battlefield, rear control personnel can operate fiber optic drones to launch covert attacks from low altitude and tricky angles such as building windows and armored vehicle ventilation openings, conducting "window breaking" and "hole drilling" strikes. The characteristics of "difficult to disconnect and stealth operation" make fiber optic drones play an important role in tactical operations such as removing key enemy nodes and tearing open defense gaps. Another advantage of fiber optic drones is closely related to the high bandwidth characteristics of fiber optic communication. Compared to radio communication links with narrower bandwidth, fiber optic cables can simultaneously transmit multiple data channels, providing clear and smooth video images, allowing operators to clearly distinguish the authenticity of tanks, hidden soldiers, etc., improving the accuracy of target recognition and reducing the waste of ammunition or missed fighter jets caused by misjudgment. In addition, fiber optic cables ensure precise control of drones by operators with low data latency. Although weak fiber optic drones with limited range and maneuverability have strong battlefield survival capabilities, they also have obvious limitations in their use. The long fiber optic cable trailing behind it is its weak point. The voyage is limited. Fiber optic cables can be extremely thin and light, with a diameter of about 0.5 millimeters for fibers with a cladding layer. A 5-kilometer-long ordinary fiber optic cable weighs only about 60 grams, but the distance between the left and right is limited. At present, the combat range of ordinary fiber optic drones is between 10 and 40 kilometers, which means that fiber optic drones can only be used as a tactical weapon for close range precision strikes on front-line positions, making it difficult to perform strategic tasks with wider depth. The air mobility is not strong. Fiber optic cables can withstand significant tensile and mechanical forces, but cannot be bent. When fiber optic drones perform complex maneuvers such as rapid hovering and large angle rolling in the air, the fiber optic cables behind the drone may become tangled, damaged, or even broken. Experimental data shows that when the turning angle of a fiber optic drone exceeds 120 degrees, the fiber optic cable is highly prone to breakage, thereby increasing the risk of loss of control. In addition, when fiber optic drones fly in dense forests, high-rise cities, or complex terrains with obstacles, the fiber optic cables are also prone to breakage. This requires operators to choose open and accessible areas as much as possible when planning flight paths, which undoubtedly increases the difficulty of control and limits the tactical flexibility of fiber optic drones. The above shortcomings also provide countermeasures for fiber optic drones. For example, a high-energy laser weapon system can be deployed to directly burn the fiber optic cables in suspicious areas, causing the fiber optic drones to instantly "lose contact". Other drone platforms can also be used to carry sharp objects such as blades to damage the trailing optical fibers behind the fiber optic drone. For example, a regular drone can wrap around the back of a fiber optic drone and use an onboard propeller to cut off the fiber optic cable, causing it to crash. Anti drone nets or high-strength adhesives can also be used to physically wrap and adhere the fiber optic drone body, causing it to lose control. Fiber optic drones, as cutting-edge equipment on the battlefield, provide a new asymmetric combat approach for modern electronic warfare. With the development of fiber optic material technology, automatic pay off technology, and intelligent flight control technology, further observation is needed to determine whether fiber optic drones can play a greater role on the battlefield. (New Society)