Verfahren zur bleibenden Markierung eines Gegenstands

Method for providing an object with a marking by means of local irradiation of the object in a predetermined object area with high-energy electromagnetic radiation, the irradiation being effected at a wavelength outside the visible range but within the optical range of the spectrum of the electromagnetic radiation, in which the material of the predetermined object area exhibits a maximum of spectral absorption and the further parameters of the irradiation being predetermined in the result of material-related prior tests in such a manner that, due to the interaction of the radiation with the molecular structure in the predetermined object area, a permanent change of the optical characteristics is induced which is perceptible when illuminated in the range of wavelengths of the absorption maximum, but the object area is not changed mechanically and/or perceptibly when illuminated with visible light.