Fibre Bragg Grating Technology
Fibre Bragg Gratings (FBGs) are made by laterally exposing the core of a single-mode fibre to a periodic pattern of intense ultraviolet light. This way an optical sensor is recorded within the core of a standard optical fiber. It reflects a narrow bandwidth of light which responds to changes in temperature and strain.
Figure: FBG working principle
Hundreds of FBG sensors can be recorded into a single optical fiber and interrogated simultaneously with a single instrument. The technology allows to monitor strain and/or temperature within large structures, particularly suited to perform design validation and test and structural health monitoring.
Besides temperature and strain, FBGs can be used to measure a variety of other physical parameters such as humidity, pressure, displacement, water leakage,.... This can be achieved using smart transduction mechanisms that convert the physical parameter into a strain value onto the FBG.