Chaos correlation optical time domain reflectometry

We propose a novel correlation optical time domain reflectometry (C-OTDR) of using broadband chaotic light. This reflectometry has the advantage over the conventional OTDR and the pseudorandom signal C-OTDR in range-independent spatial resolution. We employ a laser diode with feedback from a long fiber ring cavity as the source of chaotic probe light. Experimental and numerical studies show that the chaotic light has broad and flat spectrum, and excellent correlation properties. Using this broadband chaotic laser, we experimentally demonstrate the proposed chaos C-OTDR for locating the fiber reflection events, and analyze the spatial resolution and dynamic range. The results show that the chaos C-OTDR can realize a range-independent resolution of 6 cm and its dynamic range is at least 25 km.