Abstract:
PURPOSE: A security device for controlling colors and polarization of lights is provided to make counterfeit/falsification difficult by using optical properties of a metal and to optically identify the falsification. CONSTITUTION: A security device for controlling colors and polarization of lights comprises a metal layer(20) and a substrate(10), and a fluorescent substance layer or nonlinear substance layer. The metal layer is arranged on the substrate. A plurality of nano metal slits is arranged on the metal layer and periodically arranged while having a size smaller than incident wavelengths. The fluorescent substance layer or nonlinear substance layer is arranged between the substrate and metal layer and generates lights of different frequencies.