OFDR Spatial Resolution Optimization Using Equal Sampling and Gaussian Fitting Method

In optical frequency domain reflectometry (OFDR) system, the hardware limitations result in poor performance in spatial resolution and measurement distance, which fails to meet practical expectations. Based on the hardware foundation of an auxiliary interferometer, this paper proposed a novel joint optimization scheme of equal sampling and Gaussian fitting. During the transmission process, a fixed threshold wavelet denoising method is used for sub-band synchronous denoising to reduce the influence of phase noise. Meanwhile at the demodulation end, frequency-domain compensation is achieved by sliding window zero padding and cross-correlation Gaussian fitting. Simulation result showed that the proposed scheme can achieve 0.12mm spatial resolution within a measurement range of 420m. Compared with the existing method, the performance ratio, namely the measurement range divided by the spatial resolution, is improved at least 1.5 times, which can effectively not only improve the spatial resolution, but also expand the measurement range of the system while ensuring the detection speed.