Influence of the grating of cones shape on the performances of fiber-optic linear displacement sensor

This paper introduces the principle of a new optical displacement sensor; its main characteristic is its ability to measure over long range (millimetric) with nanometric resolution the linear displacement of an actuator performing a helical movement. Firstly, the grating of cones principle is describded. Then, geometrical modeling is proposed. The influence of the shape of the cones over the sensor performances (range, sensitivity, resolution) is studied. Finally, the calibration curves in terms of the light intensity detected as a function of the displacement are compared when planar and convex surfaces are considered.