Anti-Stokes phosphors for use in security documents

It is proposed for the application in security documents, an anti-Stokes phosphor, wherein the anti-Stokes phosphor ions having (absorber) for the absorption of electromagnetic radiation, and ions (emitter) for emitting electromagnetic radiation (anti-Stokes luminescence), wherein the wavelength of the emitted electromagnetic radiation is smaller than the wavelength of the absorbed electromagnetic radiation. The concentration of the absorber and / or the concentration of the emitter is adjusted such that a suitable for the automatic detection of the anti-Stokes phosphor Anklingzeit and / or decay time of the Anti-Stokes luminescence is achieved.