Low-coherence interferometry with homodyne demodulation capabilities for distributed fiber-optical sensors

Abstract

Distributed fiber-optical sensors (DFOS) achieve the best results while interference registration schemes are used when controlled physical field lead to the fiber length and phase difference. DFOS based on fiber-optical phase-amplitude filters (FOPAF) have a simple and reliable design, consisting of distributed sensing elements (DSE) set. However, the main problem is the stabilization of its characteristics in different areas of DSE. On the other hand, the possibilities of low-coherence interferometry with homodyne light demodulation show the possibilities of stabilizing working points, but in the Michelson fiber-optical interferometric tandem scheme. The purpose is to substantiate the option of stabilizing the operation of DSE based on FOPAF, using low-coherence interferometry with homodyne demodulation in monitoring spatially distributed physical fields. The appropriate methods are considered. The analysis of the possible experimental setup based on the low-coherence interferometry with homodyne demodulation in the interferometric tandem scheme in comparison with the variants, based on the low-mode fiber-optical fibers is established. Promising scheme of the experimental installation is presented and the requirements for components are justified. The prospects of using low-coherence interferometry with homodyne demodulation for DFOS based on DSE with FOPAF are shown. The proposed low-coherence interferometry scheme with homodyne demodulation for DFPS on DSE with FOPAF has high sensitivity, is built on affordable equipment and, accordingly, has a low specific cost for the subsequent development of monitoring system.