What it is?
Fluorescence is a light emitting effect where the outgoing light has a lower frequency than the incoming light.
How do you detect it?
Authentication of security features using fluorescence is in general done by observing the light emission and color shifting effect.
How does it work?
Fluorescence is usually achieved using special molecules, atoms, nanostructures which emit photons when their constituting atoms change energy states from higher to lower after excitation. The fluorescent elements are often mixed into inks so that they can be printed on documents and packaging. It can also be integrated into plastic.
In general, fluorescence for brand protection is an outdated technology. It may still be appropriate in extremely specific scenarios, when the supply chain involves very few manufacturers or printers. Moreover, it is limited for internal use solely since it usually requires specific UV or IR detectors (unless a low security UV lamp is used). Finally, it creates additional burdens on the brand owner for the supply and distribution of the fluorescent substance and of the detection hardware. In practice, whenever fluorescent markers are printed, it will be more effective to replace them with a Cryptoglyph®: less expensive on the manufacturing side, more secure and easier to deploy. If the fluorescent substance is used for molded plastic products, then the AlpVision Fingerprint® approach will also be more appropriate and for the same reasons: simpler, more secure, less manufacturing costs.
Field of application
Banknotes, passports, metal and plastic caps, pharmaceutical vials, and official documents.