Lightwave Technologies for Interrogation Systems of Fiber Bragg Gratings Sensors

A review of Fiber Bragg Grating (FBG) features and the different schemes of fiber sensors interrogation are reported. The interrogation system represents the key element of monitoring systems in terms of both performance and cost as it has to measure relatively small shifts in Bragg wavelength of FBG elements. An innovative interrogation system prototype for structural sensing based on a high-performance electro-optic edge filter on glass is also presented here. It provides a wavelength-dependent transmittance with a linear relationship between the Bragg wavelength shift and the output intensity change of the filter. The resulting device is the demonstration of a simple and inexpensive technology to implement low cost FBG sensors monitoring system based on innovative integrated optic functional component on glass.