Hybrid TDM/WDM based fiber-optic sensor network for perimeter intrusion detection

A distributed fiber-optic sensor system is proposed and demonstrated for long-distance intrusion-detection, which employs the hybrid time/wavelength division multiplexing (TDM/WDM) architecture. By utilizing 20 time zones and 6 wavelengths, the system contains up to 120 fiber sensing units (OSU), of which the distributed sensing distance is from 0 to 500m. So the whole sensing distance of this system could reach 60 km. The system has been demonstrated to run stably exceed six months with the false alarm rate of less than 4%.