Influences of pulse on phase-sensitivity optical time domain reflectometer based distributed vibration sensor

Abstract The influences of pulse, including the pulse width T p and the peak pulse power I peak , on phase-sensitivity optical time-domain reflectometer ( φ -OTDR) based distributed vibration sensor are investigated in this paper. A numerical simulation is performed to illustrate the relationships between pulse and temporal response trace as well as the visibility of interferential Rayleigh backscattering light. The simulation results show that the method of amplifying I peak is benefit for increasing the amplitude of temporal response trace, while it is useless for improving the visibility. In contrast, the method of broadening T p is useful for increasing the amplitude of temporal response trace by improving the visibility. Laboratory experiments are implemented by using a φ -OTDR prototype with an electro-dynamic vibration table producing stable vibration signals. The good agreement of experimental with simulated results validates the theoretical analysis.