Abstract

In this communication, the effect of the probe pulse shape on the backscattered power trace of phase-sensitive (phi-) OTDR is analyzed. In particular, the power traces obtained with rectangular and Gaussian-like probe pulses are compared, both numerically and experimentally. Our analysis reveals that the use of Gaussian-like pulses can increase the operation range and sensitivity of phi OTDR-based sensors in at least two-fold as compared with that obtained from traditionally-employed rectangular-like pulses.