Multiphoton Luminescence in Resonant Silicon Nanoparticles for Physically Unclonable Anticounterfeiting Labels

Anti-counterfeiting labels based on nanoobjects with stochastically varied parameters are of immense interests in the last decade. In addition to an object size and its coordinate, the inherent properties of nanoobjects play an important role in the label encoding. Recently, we have demonstrated physically unclonable security label with multilevel authentication based on resonant silicon nanoparticles. The label was printed using laser induced forward transfer, providing unique spatial/color coordinates and nanoparticles radius distribution. In this paper we propose additional encoding level through utilization of multiphoton-induced silicon photoluminescence.