Research on accurate position method based on code division multiplexing technology for distributed FBG system

A accurate position method for distributed fiber grating system based on code division multiplexing technology is proposed. In this paper, by using the fiber grating characteristics and code division multiplexing technology, the system are optimized. By designing delay interferometer, the optical signal modulation and demodulation are gained , which effectively improve the system's signal to noise ratio. Through the simulation experiment, the positioning detection is realized by discriminating the fiber gratings at different positions on the optical fiber. Experiments were carried out on 6m and 2.2km optical fibers respectively, the preliminary results proved the correctness and feasibility of the method.