从双光束干涉的基本原理出发，分析了高斯分布光源条件下利用傅里叶变换解调光纤法布里珀罗传感器的原理。针对高斯分布光源特点，提出直接对波长均匀采样得到的光谱数据进行快速傅里叶变换，然后利用传感器腔长与频域中峰值频率之间的关系求解传感器腔长的可行性。在此基础上，采用频谱插值技术提高了系统解调精度，并利用宽带光源和光谱仪等组成的解调系统，对所提出的方法进行了实验验证。结果表明,从实验中测得的数据与理论计算值能较好地吻合。

Based on the principle of two-beam interferometer, the demodulating theory of optical fiber Fabry-Perot sensor illuminated by Gauss distributed optical source was demonstrated via Fourier transform method. According to the characteristic of Gauss distributed optical source，the feasibility of measuring cavity length was presented by directly applying an fast Fourier transform (FFT) algorithm to the data sampled at equal optical wavelength interval and using the relation of cavity length and the peak frequency in the frequency domain. The demodulation precision was increased with frequency spectrum interpolating technology, and the experimental verification was accomplished with the help of the demodulating system constituted by broadband light source and spectrometer etc. The measured data are coincident well with theoretically calculated data.