Cantilever-based FBG sensor for temperature-independent acceleration measurement

A novel accelerometer based on a strain-chirped optical fiber Bragg grating (FBG) is proposed. The FBG is glued in a slanted direction onto the lateral surface of a right-angled triangle cantilever beam with a mass bonded on its free end. Vertical acceleration applied to the cantilever beam leads to a uniform bending along the beam length. As a result, the FBG is chirped and its reflection bandwidth changes linearly with the applied acceleration. A high sensitivity of 0.684 nm/g has been achieved in the experiment. This sensor is temperature insensitive, owning to the temperature-independence nature of reflection bandwidth of the FBG.