FBG Fiber Bragg Grating Sensors

FBGs (Fiber Bragg Gratings) are an optical sensor technology whose core element is optical light guides (optical fibers).
These optical fibers are thin glass strands that can conduct light in their core and consist of three main components:
the core, the optical cladding and one of the protective coatings.
The optical cladding reflects scattered light back into the core, ensuring light transmission through the core with minimal loss.
This back reflection is achieved by the cladding having a higher refractive index relative to the core conductor, resulting in complete reflection of the light back into the core.
During the production of the optical elements, periodic lateral variations of the refractive index in the core conductor are generated by intensive UV exposure, which allows the grating properties of the sensor element to be specifically defined.

As a result, the refractive index of the fiber changes according to the intensity of the UV light applied during production.
The periodic change in the refractive index is referred to as Fiber Bragg Grating.

FBG sensors therefore offer a sensor solution in which the optical grating properties are used as the measuring principle.
As purely passive elements, the sensors are not only mechanically robust but also completely insensitive to electrical or magnetic radiation, making them ideal for use in explosion-proof environments.

Due to the robust principle combined with the very high sensitivity, these systems are suitable for permanent monitoring of the integrity of structures such as tunnels, dams or bridges as well as for permanent monitoring and measurement of the mechanical integrity and current load of heavy-duty components in shipbuilding,
power stations and much more.
Other areas of application include the masts and rotor blades of wind turbines or the masts of sailing ships.