From Coherent Systems Technology to Advanced Fiber Sensing for Smart Network Monitoring

Coherent technology developed in the past decade for transmission over core optical networks has leveraged the fiber capacity with the introduction of polarization diversity I/Q modulation along with advanced signal processing. Meanwhile, Distributed Acoustic Sensing (DAS) over telecom infrastructure has recently gained interest, and its introduction in deployed optical networks for in-depth supervision becomes a desirable feature for telecom operators. This paper intends to show that the combination of coherent solutions and digital processing techniques implemented today in current transceiver systems can strongly benefit DAS technology: key performance parameters as sensitivity threshold and sensing range, and coexistence with data traffic can be significantly improved compared with the figures achieved by initially introduced conventional solutions.