Fiber optic displacement sensors for the measurement of a vibrating object

A description of the experimental setup, test procedure, and data-processing of an intensity-modulated fiber optic displacement sensor that has a broad linear range of analog output and transforms to digital type is presented in this article. Compared with various fiber optical sensors, this fiber sensing head has a bundle of fibers with relatively novel devices including a polarized beam splitter and two detectors to prevent confusing front and back slope in the relation of displacement and signal intensity. The real advantage of fiber optical displacement sensors lies in solving vibration testing problems for which the measured system needs a precise and high-frequency response. With fiber optical sensors, we obtained the data of the sysstem excitation as the outcome of experimentation, then transformed the experimental data through a Fast-Fourier transform system and obtained the vibration information of the testing system. From the experimental results, we proved that this device is economical and feasible.