Temperature-independent fiber Bragg grating strain sensor system

This article demonstrates the indirect method of strain measurement using optical fiber sensors. The primary reason for this article is demonstrate the possibility to design cheap and small system for measurement of optical signal from fiber Bragg grating sensor (FBG) excluding optical spectrum analyzer. The proposed uncomplicated measurement system contain two FBGs inscribed in the same optical fiber which makes their temperature sensitivities equal. This property allows to use gratings with matched wavelengths as a following filters. The paper shows a results of a force measurement using matched FBG array and measuring system which presents real time measure.