Abstract: Genuine U.S. Federal Reserve Notes have a consistent, twocomponent intrinsic fluorescence lifetime. This allows for detection of counterfeit paper money because of its significant differences in fluorescence lifetime when compared to genuine paper money. We used scanning two-photon laser excitation and the time-correlated single photon counting (TCSPC) method to sample a ~4 mm 2 region. Three types of counterfeit samples were tested. Four out of the nine counterfeit samples fit to a one-component decay. Five out of nine counterfeit samples fit to a twocomponent model, but are identified as counterfeit due to significant deviations in the longer lifetime component compared to genuine bills.
The fluorescence lifetime is investigated REF , it is found using a two-photon laser excitation and time-correlated single photon counting (TCSPC) method, significant differences in the duration of fluorescence are observed when comparing genuine and counterfeit notes.
Detection of counterfeit US paper money using intrinsic fluorescence lifetime
Optics express
Optics express
Medicine Physics