Self-calibrated interferometric-intensity-based optical fiber sensors

摘要: This paper presents self-calibrated interferometric-intensity-based optical fiber sensors, which combine for the first time interferometry and intensity-based devices into a single sensor system. The involves an extrinsic Fabry-Perot (FP) interferometric cavity. broadband light returned from FP cavity is split two channels in such way that one channel has coherence length much longer than doubled air-gap separation so generates effective interference, while other short no interference takes place. As result, signal with long yields information about proportional only to source power, attenuation, loss factors path. To eliminate fringe direction ambiguity relative measurement limitations associated designed it operated over linear range between valley peak of channel. Moreover, ratiometric signal-processing method applied signals obtain self-calibrating compensate all unwanted factors, including power variations bending losses. Various pressure temperature sensors based on interferometric/intensity-based scheme are designed, fabricated, tested. Experimental results show resolution as high 0.02% full scale can be obtained both measurements.