Abstract

A modified optical fibre based Mach-Zehnder interferometer was applied as a sensor to detect wiretapping in long transmission optical fibre lines. When the detection line was not disturbed, the detectors registered a series of pulses without changing their peak power. For robust detection of any alarm situation we proposed algorithm to minimize false alarm rate. Moreover, slow environmental fluctuations were continuously monitored and compensated by polarisation controllers. We measured the response characteristics of the sensor to typical disturbances resulting from human interference in the telecommunications cable, which confirmed the high performance of the sensor.

© 2020 The Author(s)