Fiber-optic sensors enable measurements in environments where electrical sensors reach their limits. Unlike electrical measurement methods, the purely optical measurement method is completely insensitive to environmental influences.

FBG sensors consist of a glass fiber into which one or more fiber Bragg gratings are inserted. These fiber Bragg gratings are formed when the refractive index of the glass fiber is cyclically changed during manufacture under the influence of a laser. When the glass fiber is illuminated, a characteristic wavelength is now reflected and this wavelength changes under strain.