This thesis work is in the more general and huge frame of biosensors applied to the biomedical sector. The developed sensor is dedicated to concentration measurement of chemical substances. We use a biochemical reaction in the vicinity of the core of an optical fiber which modifies the propagation conditions of the optical wave by evanescent coupling. The sensitivepart involves an intrinsic optical fiber Fabry-Pérot interferometer. The principle of this sensor combines two optical aspects :• A biochemical fonctionnalisation of the optical wave guide in order to make the effective index dependent on the concentration of the substance targets by evanescent coupling. This part of the optical fiber is addressed through a Fabry-Pérot interferometer cavity.• An interferometry detection unit which performs accurate measurements of the optical length of the cavity.The interest of such a system is to offer reduced dimensions; i.e. the size of an optical fiber. The integration on a single fiber of several sensors, with different cavity lengths, gives us the ability to achieve a multispecific probe. The detection involves classical interferometry techniques such as coherence modulation.
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