Advances in phase-sensitive optical time-domain reflectometry

Phase-sensitive optical time-domain reflectometry (Φ-OTDR) has attracted numerous attention due to its superior performance in detecting the weak perturbations along fiber. Relying on ultra-sensitivity of light phase tiny deformation fiber, Φ-OTDR been treated as a powerful technique with wide range applications. It is fundamental extract scattering wave accurately and methods include coherent detection, I/Q demodulation, 3 by coupler, dual probe pulses, so on. Meanwhile, researchers have also made great efforts improve Φ-OTDR. The frequency response range, measurement accuracy, sensing distance, spatial resolution, accuracy event discrimination, all enhanced various techniques. Furthermore, lots researches applications kinds fields carried out, where certain modifications techniques developed. Therefore, remains booming both