摘要： A compact dual-parameter fiber-optic sensor based on concatenation of a fiber peanut taper and long-period fiber grating (LPFG) has been proposed and experimentally demonstrated for simultaneous measurement of strain and temperature. Due to the presence of fiber peanut taper, part of the fundamental core mode could be coupled into fiber cladding modes, part of which would be re-coupled into the fundamental core mode and interfere with the remnant core mode light at the LPFG. Due to the phase matching condition of the LPFG, the interferometric spectral pattern could only be acquired within the transmission resonance spectral envelope determined by the LPFG. Experimental results indicate that the highest
strain and temperature sensitivities of the proposed fiber modal interferometer reach -0.564 87 nm/mε and 57.29 pm/°C, respectively. By employing the distinct strain and temperature sensitivities of two interference dips, a sensor matrix could be set up for simultaneous dual-parameter measurement.