Localization of a loss-inducing perturbation with variable accuracy along a test fiber using transmission-reflection analysis

We report on the detection of a loss-inducing perturbation with variable localization accuracy along a test fiber based on the analysis of transmitted and reflected powers of an unmodulated continuous-wave light source. The required accuracy of localization is provided by suitable distribution of the differential reflectivity along the fiber. The localization accuracy for a strong disturbance has been estimated as ± 1.0 m along the 3.939-km single-mode test fiber and as ± 5.0 mm along a designated 10-cm fiber part for both strong and weak perturbations.