Abstract: A device for applying light conductive fibers onto substrates and having a mounting yoke, a holding device and a stamping device. The holding device is configured as a U-shaped base body with an upward arching outside area having guide grooves and holders for installing the fibers in the device. The stamping device consists of a stamp, a stamp neck and a stamp head, which are inserted and linearly guided in the U-shaped die sink in the holding device. The device ensures a precise positioning of fibers and in particular of functional units in fiber segments. Fiber breaks can be nearly ruled out with the application method. The separating foils ensure that the device can be removed after the adhesive has hardened, so that no force is exerted onto the fiber through excess adhesive that sticks.