Twin-Core Fiber-Based Erbium-Doped Fiber Laser Sensor for Decoupling Measurement of Temperature and Strain

In this paper, a novel all-fiber laser sensing configuration for decoupling measurement of strain and temperature based on the twin-core fiber (TCF) with an in-line embedded fiber Bragg grating (FBG) is proposed and experimentally demonstrated. An erbium doped fiber ring laser is built, with an optical signal-to-noise ratio higher than 40 dB and a power instability of 6.75 μW in 1 h. Due to the different spectrum responses of the TCF and FBG to the uniform variation of strain and temperature, the decoupling measurement for these two measurands could be achieved by real-time monitoring both the center wavelength shift and the peak power variation.