Fault Location In WDM-PON By Using Wavelength Tunable Random Signal

With the development of optical fiber communication technology, wavelength division multiplexing passive optical network (WDM-PON) is considered as the next generation accessing network because of its large capacity and high privacy. WDM-PON realizes the communication between point to many points and there are many fiber branches and remote nodes. So it is important to recognize the fault fiber links and locate the faults.Based on the previous work of our group, wavelength tunable chaotic laser and amplified spontaneous emission are used as the probe light of the optical time domain technology, respectively, and by correlation the returned probe light with its delayed duplicate, precious fault location technology in WDM-PON is obtained.Focusing on this new technology of fault location in WDM-PON, the research work is mainly summarized as follows:1. We introduce the development of PON, especially WDM-PON technology, and sum up the advantage and disadvantage of the main fault location technology in WDM-PON.2. By using a mode-select optical feedback into FP laser, tunable chaotic light is obtained. We use side mode suppression ratio and the largest Lyapunov exponent to measure its property and analysis some influence factors to the chaotic laser in experiment. 3. The wavelength tunable chaotic laser is used as the probe light, with correlation calculation, A precise fault location technology is obtained in experiment. The effect of chaotic laser’s property on the detection results is also analyzed.4. Because there is a mode separation in FP chaotic laser, we use amplified spontaneous emission with broadband optical spectrum as the probe light, a more broad fault location technology is obtained. In our experiment, different faults is detected, such as the fiber end, FC/PC end, and its dynamic range is calculated.