Crosstalk analysis of the in-line quasi-distributed low-coherence low-finesse Fabry-Perot fiber-optic interferometric sensors

A crosstalk analysis of the in-line quasi-distributed low-coherence low-finesse Fabry-Perot fiber-optic interferometric sensors is presented in this paper. The appropriate selection of the sensor cavity lengths eliminates the presence of the second-order intermodulations. Therefore, the intermodulations that can significantly influence the sensors crosstalk are the third-order intermodulations. For a typical sensor configuration by choosing the in-fiber mirror reflection coefficient lower than 0.5%, the minimum achievable signal-to-intermodulation ratio is higher than 26 dB for a maximal possible number of sensor placed along the fiber that satisfies broad range of requirements for most of the quasi-distributed measurements of typical parameters such as strain and temperature. (C) 2016 Elsevier Inc. All rights reserved.