Abstract
The objective of this study is to demonstrate a new technique for fiber ranging and fault locating. By using semiconductor laser and extracting the time delay signature (TDS) of dynamical states resulting from the optical feedback, we developed the selfmixing optical time domain reflectometry (SMOTDR). Experimental results show that 2 cm resolution and -32 dBm sensitivity had been achieved. And due to the improve of setup, SMOTDR has already existed in fiber system so it has the potential to become a built-in self-detector. On the other hand, we compare SMOTDR with chaotic correlation optical time domain reflectometry (CCOTDR), besides SMOTDR has the compacter setup and simplified processing program, moreover it has the higher ranging sensitivity, furthermore due to the difference on setup the ranging performance would be better than CCOTDR in long testing length.