The use of fibre optics in the telecommunications field has been gaining more and more recognition among end customers. The demand for optical and optoelectronic components and modules has risen dramatically. The different requirements resulting from the measured distances and operational environments have led to a multitude of special solutions.
With OTDR and fibre optic sensors, fibre optic networks and other critical infrastructures can be monitored in real time. Errors are reported immediately and failures avoided altogether.
Fibre optic connections form the backbone of all state-of-the-art data networks. Even the smallest disturbances can have serious consequences – including complete power failure. It is, therefore, important to protect the cables and relevant infrastructure from sabotage, espionage, and environmental damage. Optical real-time monitoring is a proven means of this. In optical time domain reflectometry (OTDR), short light pulses (ns to µs) are sent into the fibre and the backscattering based on Rayleigh scattering is evaluated. The running time of the pulses can then be used to detect the exact location of errors, attenuation, and manipulation within seconds. In this case, the system triggers an alarm.
This type of optical network monitoring not only protects against network failures and physical damage, but it also contributes to data security: With comparatively simple methods such as fibretapping, spies and criminals repeatedly try to intercept sensitive information during transmission. However, this results in attenuation losses, which can also be detected and localized via OTDR.
In an increasingly interlinked world, optical technologies are not only used to monitor data networks. Legislation also demands the protection of other critical infrastructures (KRITIS). These include electricity, gas, and water networks, as well as healthcare and financial networks. Fibre optic sensors are used wherever the protection of a facility is required. For example, they recognize when a cable duct has been broken open or a manhole cover has been lifted. The purely optical systems have a decisive advantage: they do not require an operating voltage and therefore function perfectly, even in the event of a power failure.