Detection of dynamic signals from multiplexed SOA-based fiber-ring laser sensors.

A simple matched filter demodulation configuration for detecting dynamic signals from multiplexed semiconductor optical amplifier (SOA)-based fiber-ring laser sensors is investigated theoretically and experimentally. It is feasible for multiple points fiber Bragg grating sensing because the inhomogeneous broadening of the SOA source makes it possible to produce multimode lasing without mode competition. The best operating points for matched filter demodulation and the wavelength demodulation range are investigated. In the experiment, the simultaneous dual-channel detection of dynamic strains at high frequencies is presented by using piezoelectric transducers. An example application for simultaneous two-channel ultrasonic detection has been successfully demonstrated. The detection system design is simple, low cost, and high precision, making it attractive for applications in structure health monitoring.