Interferometric phase sensor using single-ended polarization maintaining fiber in Sagnac interferometer

摘要

An interferometric phase sensor is proposed and demonstrated for strain sensing based on a Sagnac interferometer including polarization maintaining fiber (PMF). Since the conventional PMF Sagnac interferometer includes a PMF in the loop by splicing both ends with the two ends of 50:50 coupler, it has been difficult to apply the two-ended PMF in the practical applications. In this paper, we propose a simple configuration by adding one more 50:50 coupler in the Sagnac loop to connect the PMF with one splicing process for a remote sensing position. Instead of tracking the shift of periodic spectrum by optical spectrum analyzer, higher sensitive method is proposed by interrogating a phase variation of the interferometric optical signal from the modified Sagnac interferometer including single-ended PMF.