Coupling Intensity Measurement Based on White Light Interferometry in the Distributed Long PMF Sensors

In polarization-maintaining fiber (PMF) sensors, the detected coupling intensity descends obviously with increments of the transmission distance. A long PMF of more than 500 m is tested, the phenomenon of intensity attenuation is investigated experimentally, and a modified method with a reference point is proposed to measure the coupling intensity accurately. The experimental results show that the coupling intensity can be compensated effectively. The absolute error of coupling intensity is less than 0.59 dB.