title: Detection of counterfeit U.S. paper money using intrinsic fluorescence lifetime.
abstract: Genuine U.S. Federal Reserve Notes have a consistent, two-component 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 approximately 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 two-component model, but are identified as counterfeit due to significant deviations in the longer lifetime component compared to genuine bills.
authors.affiliation: Department of Biomedical Engineering, Yale University, New Haven, CT 06511, USA.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Chia
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Levene