In this work, we present a theoretical model and experimental characterization of a sensor structure composes by singlemode optical-fiber rings for measuring small displacement. The principle of the sensor is based on the continual loss of evanescent radiation in the external side of the bending region of the fiber. To reduce noise problems and increase sensibility, we have developed several modulator and demodulator electronic circuits to process the optical signal.
Keywords: sensor, optical fiber, lost by curvature.