Nonlinear phase compensated OFDR based on match fourier transform algorithm

The nonlinear phase of beat signal in Optical Frequency domain Reflectometry(OFDR) has become a bottleneck to its utilization. In this paper, a method to compensate nonlinear phase based on Match Fourier Transform algorithm(MFT) is presented. The nonlinear phase of beat signal is represented as a polynomial phase function, then the coefficients of the polynomial phase function are obtained from an auxiliary interferometer through the polynomial regression algorithm. Finally, the nonlinear phase in main OFDR interferometer can be compensated by Match Fourier Transform algorithm. The experimental results show that the method can effectively suppress the side lobe of the reflection peak and achieve a spatial resolution of 0.2m at 4.3km. The experiment results verify the effectiveness of the proposed algorithm.