Interrogation of fiber bragg grating sensor based on Er-doped fiber laser

A novel interrogation of fiber Bragg grating (FBG) in a strain sensor, which is based on Er-dopedfiber laser's transient regime, is reported. The applied strain on FBG changes the laser cavity loss, which in turn modifies the laser's transient regime. The strain value can be obtained by measuring the build-up time of the laser. This method translates wavelength shift information into time domain that can be accurately measured with low-cost electronic devices. In the experiment, the strain sensitivity can be adjusted by simply controlling the pumping level of the laser, a sensitivity of 1.66 με/μs is achieved under fitful pumping level.