Plastic fiber optics are suitable for universal applications with low space requirements for object detection. Glass fiber optics are used in demanding environmental conditions with high temperatures and are resistant to chemicals. For radiation through foils or applications with high light power, they offer further advantages through the especially low damping. The flexible fiber optics with various head shapes can be integrated in nearly any system design. The detection range is dependent on the fiber optics and amplifiers used. Fiber optics can be used with the throughbeam principle or with scanning function. As a fiber array with multiple light beams, they can be used to detect especially small objects.