Opt Lett. 2018 Apr 01;43(7):1499-1502. doi: 10.1364/OL.43.001499.

Sidelobe apodization in optical pulse compression reflectometry for fiber optic distributed acoustic sensing.

Optics letters

Juan José Mompó, Sonia Martín-López, Miguel González-Herráez, Alayn Loayssa

PMID: 29601014 DOI: 10.1364/OL.43.001499

Abstract

We demonstrate a technique to reduce the sidelobes in optical pulse compression reflectometry for distributed acoustic sensing. The technique is based on using a Gaussian probe pulse with linear frequency modulation. This is shown to improve the sidelobe suppression by 13 dB compared to the use of square pulses without any significant penalty in terms of spatial resolution. In addition, a 2.25 dB enhancement in signal-to-noise ratio is calculated compared to the use of receiver-side windowing. The method is tested by measuring 700 Hz vibrations with a 140  nε amplitude at the end of a 50 km fiber sensing link with 34 cm spatial resolution, giving a record 147,058 spatially resolved points.

Publication Types

• Journal Article