Study On Fiber-optic Displacement Sensor

Modern optical fiber sensors owe their rapid development to the achievements of technologies in fiber fabrication. They have many advantages over traditional sensors, such as high sensitivity, insensitivity to influence of electromagnetic field, good solution, small volume, low price, etc, so it has a great future in micro-machine system.In this paper, two kinds of optical fiber sensor which are based on light intensity modulation are studied, the micro-bent fiber-optic displacement sensor and the reflective fiber-optic displacement sensor. At first, according the theory of the sensor, the mathematics model was built, and the key parameters were analyzed, then the reasonable parameters could be chosen. The second, two kinds of mechanic structure were designed and the detective circuit was made. In micro-bent sensor, a new kind of micro-bent mechanism was designed which replaced the traditional construction. That simplified the whole system structure, and declined the difficulty of manufacture deeply. In order to increase the range, the lever structure was introduced into reflective sensor. The reflective board was chosen strictly, enhancing the capability of against disturb. At last, the light given out from the sensor was measured and analyzed; a relation between displacement and light intensity was obtained.This paper is instrumental in study of miniaturization fiber optical displacement sensor.