Dynamic sensors based on fiber-ring laser using a semiconductor optical amplifier

摘要

In this paper, we theoretically and experimentally demonstrate a dynamic strain sensor system utilizing a semiconductor optical amplifier (SOA)-based fiber-ring laser (FRL). The output of the laser cavity connects to a fiber Fabry-Perot (FFP) filter as an intensity demodulator. The SOA-based FRL incorporates fiber Bragg gratings (FBGs) as wavelength selective components for the fiber laser. The optical signals reflected from the FBGs are detected by photodetectors (PDs) after filtering by the FFP filter and fiber bandpass filters (BPFs). The change of the external dynamic strain will cause the spectral-shift of the reflected light of the FBG which can be dynamically monitored by the change of the output light intensity from the filters. The experimental result shows that the sensing system proposed here has a good response to the dynamic strain signal. In the meantime, we also simulated the spectra matching of the FFP filter and the FBG, and then we obtained the optimal response range near the resonance peak of the spectrum of the FFP filter. The system demonstrated here has a simple structure and low cost, which make it attractive for dynamic strain detection in structural health monitoring.