Chinese researchers have been able to listen to people’s voices from a distance of hundreds of meters with an optical fiber cable
Scientists have been able to design a system that receives sounds in fiber optic cables and will provide the ability to listen to other people’s conversations up to 800 meters away. Optical fibers can do this by transmitting information using light pulses and are commonly used for broadband networks, but they can be sensitive to changes in the environment caused by noise.
Chinese scientists and researchers have been able to create a system to receive sound through one side of a fiber optic cable and transmit it to the other side. These cables are sensitive based on environmental pressures that exist outside of acoustic waves such as talking, and this causes a security risk.
The research results of Tsinghua University researchers were published by the arXiv website, which says: “Optical fiber networks are being widely implemented around the world because they not only make data transmission easier, but also allow you to get more information. The various functions of optical fiber networks, including earthquake detection, urban traffic flow monitoring, and making discoveries related to underground structures, have a positive effect on people’s lives. However, they also present potential security issues that should be carefully considered.”
Fiber optics is used for broadband all over the world these days, because the data transmission speed is very high and affordable. As the name of this network suggests, fiber cables reach the customer’s location (home or office) directly. Now, since these cables can receive audio signals without any additional equipment, it is possible to listen to the signals and recover them at that end of the cable.
The Chinese have been able to make a device that detects the change of light caused by people talking near the optical fiber. In these tests, the sound that reached the opposite side of the cable was not clear, but it could be understood with the sound optimization methods in the computer.
Scientists say that converting information into intelligible sound in this way requires complex equipment and special conditions, but it is completely possible. They claim that materials such as metal and glass can be used to cover the fiber to prevent eavesdropping, because with this, the cables are less able to receive optical changes caused by sounds.