Range Finding and Fault Locating with Chaotic Signal

In this paper, we review our recent works on range finding and fault locating in optical network and wire with chaotic signal. Using a distributed-feedback semiconductor laser with optical feedback as chaotic source, we developed a prototype chaotic optical time domain reflectometer which can achieve a range- independent resolution of 4cm and measurable distance of about 70km. We further present the measurement of faults in the wavelength-division-multiplexing passive optical network (WDM-PON) by using a wavelength-tunable chaotic laser. Moreover, we also demonstrate the location of wire faults or impedance discontinuities with chaotic signal. Our results show that the fault location using wideband chaotic signal is a promising method of precise diagnoses for WDM-PON and electric cables.