Authentication and Testing of Banknotes Using Laser Multiphoton Electron Extraction Spectroscopy (MEES)

In laser multiphoton electron extraction spectroscopy (MEES), the photo-charges extracted from a surface by pulsed beam are recorded as function of wavelength. We report first application this to banknotes. Various banknotes different countries, authentic and counterfeit, have been tested. The results indicate that MEES spectra both informative (many peaks) reproducible. allow for clear distinction between counterfeit Actually, provides unique fingerprint banknotes, so various forgery methods (printer used) is also possible.