Opto-electronic oscillator: Applications to sensors

Abstract

Optoelectronic oscillators (OEO) have been studied since many years now, the research activities being oriented towards the improvement of the oscillator. In this paper the using of an OEO as a sensing system based on the high sensitivity of its oscillation frequency to the fiber length is demonstrated. A slope of -75 kHz/mm has been obtained by tuning the length of a free space path inserted in the optical loop. An accuracy of 0.54% by measuring of the refractive index of a Plexiglas plate has been recorded. Other sensing structures are also proposed.