POF vibration sensor based on speckle pattern changes

Abstract

A method of sensing vibration using detection of changes in the spatial distribution of energy on the speckle pattern in the output multimode optical fiber is presented and demonstrated. The implementation of sensor consists of a small length of fiber which is isolated and sensitive to ambient vibration. The projection of the speckle pattern is directly recorded by a CCD camera at the outlet end of the fiber and processed changes in the intensity distribution. The sensor is simple, inexpensive and can be implemented to measure vibrations in engine, machines or buildings.