Study of a coupling fiber-optic sensor for vibration measurement

A new kind of coupling fiber-optic vibration sensor is presented base on the principle of fiber-optic coupler´s coupling output is sensitive to the variation of coupling region´s length. A prototype fiber optic vibration detection system has been successfully developed, including a sensor head, a low-cost control unit and a software package for signal processing with high resolution. The response of a simply supported beam when imposed with periodic vibration and shock is measured with fiber-optic sensor and piezoelectric sensor; close agreement is obtained between the response of fiber-optic sensor and high precision piezoelectric sensor. Experimental results indicate that the fiber-optic coupling sensor is an ideal candidate for a simple and highly precision vibration sensor.