Sistema de interrogação de redes de Bragg :filtro de borda

Abstract

Fiber Bragg Gratings (FBG) based fiber-optic sensor (SFO) technologies have been developed rapidly and gaining great importance in the monitoring of many physical variables due to the excellent properties of optical fibers, range of applications. In addition, the need to reduce the cost of interrogation systems, aiming at the growth in the implementation of sensors. This work consists in presenting a technique of interrogation of sensors based on FBGs on optical fibers of silica. A sensing FBG that reflected optical intensity is modulated by an edge filter implemented through a coarse w avelength division multiplexer (CWDM). Through a previously performed characterization, this technique allows monitoring of the Bragg wavelength (B), which is one of the main parameters of the FBG, without the use of expensive and delicate instruments such as optical spectrum analyzers (OSAs) or commercial interrogators specific for FBG sensors. The system was developed using low cost electronics and an optical arrangement composed of a broad spectrum light source and some passive components widely used in telecommunications, as well as acquisition software developed in LabVIEW®. The results obtained in the laboratory allow us to conclude that the proposed technique allows the design of an interrogation system with compact, precise and low cost hardware for sensors based on FBGs.