Model analysis of single-mode optical fiber extrinsic Fabry-Perot interferometric sensors

We revise the demodulation model for single-mode optical fiber extrinsic Fabry-Perot interferometric sensors on account of mode-coupling theory and manufacturing imperfections of fiber sensors. This new model can be used to estimate the large system errors of absolute measurements and explain the big difference of demodulation results with different incident central wavelengths of light source. The measurement error of traditional free-space plane-wave model in demodulating cavity-length variation of fiber sensors is also analyzed.