Brillouin Optical Time Domain Reflectometer Optical Signal Analysis And Detection

In this dissertation, we first introduced the principle, characteristics and applications of optical sensing technology. We elaborated the distributed optical sensing system which is a branch of the optical sensing technology, specially, we emphasized the analysis of the sensing and signal detection principles of Brillouin scattering distributed sensing system.Based on the introduction of the characteristics and sensing principles of distributed optical sensing system, we deduced the optical pusle propagation equation suffering from the dispersive and nonlinear effect in the fiber. Furthermore, we simulated this process using the split-step Fourier method, and we also analyzed the impact on our sensing system of this phenomenon.We then proposed to utilize the Morlet Wavelet Transform as a scheme for the Brillouin scattering signal processing after analyzing the characteristics and technology to improve the detection performance of the Brillouin back scattering signal, and we also explained the principle and features of this method in detail.However, we have some specific demands in our sensing system practically. Thus, we have improved the algorithm using the Morlet Wavelet Transform to detect the envelope of the signal in some aspects, designed the whole realization scheme of the signal processing over again.Finally, we did some simulations on this algorithm, compared and analyzed the results with the ones using Hilbert Transform processing method in many aspects , applied the new method to practical BOTDR signal and concluded that the method we proposed in this dissertation was obviously better than the signal processing method based on the Hilbert Transform.