Optical Fiber Position Sensor Using A Frequency Modulated Semiconductor Laser

The method for measuring non-contactly the position of an object using an optical fiber and a frequency modulated semiconductor laser is proposed. This method uses the coherent FM heterodyne principle of the Michelson interferometer. The optical fiber gives the flexibility to the system. The maximum detection range was limited to several meters by the speckle effects to the diffuse targets and the dependence of the semiconductor laser.