Fiber-Optic Interferometry and Phase Generation-Based Micro-Vibration Estimating System

Abstract

This research presents a novel contactless micro-vibration estimating system that combines a Michelson fiber-optic interferometer and phase generation carriers based on calculation of the arc tangent. The system utilizes a narrow-band light source, a coupler, and a non-equilibrium Michelson fiber-optic interferometer to measure micro-vibrations on the surface of an object. One path of the light irradiates the object's surface vertically using an optical-fiber self-focusing lens, while the other path is reflected by a device at the reference arm's optical fiber. The light paths are then coupled, detected by a photoelectric coupler (PD), and processed by a data processing module. Additionally, the data processing module generates carrier waves to control a phase modulator on the interference arm. The resulting measurements are obtained using a phase demodulation technique based on the calculation of arc tangent (ARCTAN). The proposed system exhibits high flexibility, excellent response, and is unaffected by light intensity and visibility drifting, enabling online measurements of contactless micro-vibrations.