Axial and angular displacement fiber-optic sensor.

An intensity-based fiber-optic sensor for measuring axial and angular displacement has been designed and tested in a controlled laboratory environment. In addition, a mathematical model allowing the simultaneous calculation of the three desired parameters needed to characterize the tilt and the position of a surface under investigation is described. Preliminary tests show good agreement between the theory and the experimental results and show the sensor's potential for application in the manufacturing industry for position and vibration control. The sensor shows significant improvement in angular range over previously reported methods. An axial displacement range of 2 mm, with an accuracy of 40 mum, and an angular displacement range of 40 mrad, with an accuracy of 0.5 mrad, are demonstrated. Suggestions for further improvement of the range and the sensitivity of the sensor are also described.