Sub-micron position sensor with a fiber-optic interferometer

The wide applications of piezoelectric transducers in position server systems make the measurement and control of sub-micron displacement more and more important these days. In this paper, the authors propose a novel system based on a fiber optic interferometer and digital signal processing techniques. The size of the sensor is reduced by the fiber optics and the precision of measurement is assured by the digital analysis of the linear interference fringes. In their experiments of evaluating two types of piezoelectric transducers, a sensitivity of 5 nanometers has been realized