Authentication in the THz domain: a new tool to fight couterfeiting

Overview & Synopsis

Introduction: In the present work, we propose a new approach based on the use of the spectral signature of diffraction gratings engraved on one side of smart cards to be authenticated. The etched substrate acts as a dielectric waveguide associated to a 1D diffraction grating [1]. When the coupling conditions are verified, the reflected and transmitted THz spectra exhibit extinction lines (m-lines) that can be used as a broadband and rich spectral signature. For a given incident angle, the number of m-lines, their frequency positions and depth depend on the geometrical dimensions of the structure [2]. Hence, a unique etching scheme leads to a unique spectral signature. We first focused on simulations and experimental validation of the proposed authentication method that we would present to the 9 th THz days.