Optical strain gauge with high spatial resolution

Abstract

A technique to enhance the spatial resolution of typical fiber Bragg grating-based strain gauges has been experimentally verified in this study. Just analyzing the intensity of the reflection spectrum of a sampled fiber Bragg grating, its inner deformation profile has been obtained with a spatial resolution of DL \ 1 mm. The proposed method employs a synthesis algorithm to retrieve the longitudinal axis strain profile of a sampled fiber Bragg grating glued to an asymmetric plate. The achieved experimental results have been compared to the mechanical simulations of the employed plate, exhibiting a good response even without compensating the residual stress provoked during the installation process.