Quantitative analysis of interferometric interrogation technique used for πFBG sensors

Abstract

In this study, we conduct a quantitative analysis of the interferometric-based phase-sensitive interrogation principle for πFBG sensors using numerical simulations. The path imbalance of the interferometer arms and the line-shape function of the light signal from the πFBG sensor are critical factors influencing the sensitivity and dynamic range characteristics of the interferometric interrogation principle. Our analysis reveals several unique response characteristics that will be valuable for designing and optimizing interferometric interrogation principle using πFBGs as sensing elements. The simulation results are validated through experimental studies on πFBG sensors with in-house fabricated fiber-based Mach–Zehnder interferometers, which have path length differences of 10 mm, 19.40 mm, 28.90 mm, and 37.10 mm, respectively.