Fiber Bragg Grating sensors


A fiber Bragg grating (FBG) is a type of wavelength reflector written in a short segment of optical fiber (1-10 mm) which reflects particular wavelengths of the light coupled into the fiber. This grating consists of periodic variation of the refractive index of the fiber.

A deformation of the component and as such of the applied optical fiber will induce strain in the optical fiber, which leads to a shift of the reflected wavelength. By applying the correct gauge factor, the wavelength shift can be translated into a strain value.

Case: Control arm with integrated sensors

The sensor system consists of two optical fibers with a series of sensors. With the particular placement of the sensors in the component, bending and torsion results are de-coupled.

The sensors were further calibrated with respect to torsional and flexural stiffness. Small, manual bending and torsion moments are already sufficient to be visible on the reading device.