Interferometric fiber strain sensor

Abstract

This paper proposed a strain sensing system using two-stage optical low coherence Mach-Zehnder interferometry. A 1.3-μm wavelength distributed feedback laser for an optical ruler assisted stepper motor was implemented to achieve 19.3-nm resolved characterization. The interferogram calibrated by the stepper motor combined with optical ruler on a 3-meter long fiber then demonstrated a 2.78-nε high resolution strain sensing. It successfully demonstrated that a stable stepper motor can further improve the optical ruler encoder to establish a high sensitivity and high resolution interferometric strain sensor.