Fiber-optic sensor for distance and velocity measurements using speckle dynamics

Abstract

A fiber-optic sensor for distance and velocity measurements is described which is based on dynamic properties of speckles formed by two illuminating laser beams. This sensor is composed of two optical-fiber laser guides and an optical-fiber-array spatial filter consisting of linearly arrayed endfaces of optical fibers. The measurable ranges of distance and velocity and their accuracies are expressed in terms of the sensor's configuration parameters. The configuration for accurate sensing over a wide range is discussed. The usefulness of this sensor is confirmed by experiments.