Demonstration of fiber-optic distributed monitoring system using birefringent optical circuit synthesis

A novel fiber-optic distribution monitoring system using birefringent optical circuit synthesis (BOCS) method to monitor the external influences on the fiber is demonstrated. The detection mechanism is based on the synthesis of the transfer function of sensing fiber by using the measurement values of Stokes parameters of transmission light with a optical frequency scanning. The sensing fiber is modeled as one with the birefringence distribution characteristic and is divided into a series of birefringent lattice segments. The mode coupling angle at each birefringent segment is taken as the sensing parameter and its variation distribution as the perturbation distribution along the fiber length can be derived from two profiles of mode coupling angle obtained from the BOCS. The operation principles of the proposed system is described and several experimental results are demonstrated. At last, the discussions on the experimental results and the limitations of the proposed detection method are presented.