Simultaneous Force and Temperature Measurement Using S Fiber Taper in Fiber Bragg Grating

An ultracompact optical fiber sensor based on an S fiber taper Mach-Zehnder interferometer (SFT-MZI) embedded in fiber Bragg grating (FBG) is proposed and experimentally demonstrated for simultaneous force and temperature measurement. Experimental results show distinctive spectral sensitivities of -48.56842 nm/N (~54.97 pm/με) and 14.71 pm/°C by the SFT-MZI, and 1.30588 nm/N and 10.13 pm/°C by the FBG. The SFT-MZI, exhibiting an opposite force response as compared with that of the FBG, is highly sensitive to force. The force and temperature calculated by the sensor matrix agree well with the actual force and temperature in the experiment.