Border management and security challenges are increasing considerably in recent years. One of the major concerns is counterfeiting and fraudulent use of identity and other travel documents for crossing border controls. This poses serious threats and safety concerns worldwide, considering the scenario of terrorism and illegal migration across the world. Hence, advanced technologies with improved security features becomes essential to strengthen border security and to enable smooth transits. In this paper, we present a novel dual waveguide based invisible fluorescence security feature with lifetime discrimination and a simple validation system. Molecular fluorescence and lifetimes from the rare earth doped waveguides can be used as additional security features in the identity documents. The validation system consists of a modulated excitation source and fast photo-diodes which helps in the simultaneous detection of multiple security features from the fluorescence waveguides. The rare earth doped fluorescence waveguides are embedded into the identity document as micro-threads or tags which are invisible to the naked eye and are only machine readable. Rare earth fluorescence materials have higher sensitivity and selectivity as they absorb only specific ultraviolet (UV) or visible (VIS) wavelengths to create corresponding fluorescent emissions in the visible or infrared wavelengths. Herein, we present the results based on the fluorescence and fluorescence lifetime spectroscopic studies carried out on the terbium (Tb) and dysprosium (Dy) doped waveguides. The different emission wavelengths and lifetimes of these rare earth elements is a key differentiating feature, providing selectivity and security to the detector systems.
Border security challenges and immigration issues are increasing considerably in recent years. Counterfeiting and fraudulent use of identity and other travel documents are posing serious threats and safety concerns worldwide, ever since the advancement of computers, photocopiers, printers and scanners. Considering the current scenario of illegal migration and terrorism across the world, advanced technologies and improved security features are essential to enhance border security and to enable smooth transits. In this paper, we present a novel dual waveguide based invisible fluorescence security feature and a simple validation system to elevate and strengthen the security at border controls. The validation system consists of an LED (light emitting diode) as excitation source and an array photodetector which helps in the simultaneous detection of multiple features from the fluorescence waveguides. The fluorescence waveguides can be embedded into the identity document as micro-threads or tags which are invisible to the naked eye and are only machine readable. In order to improve the sensitivity, rare earth fluorescence materials are used which absorb only specific ultraviolet (UV) or visible (VIS) wavelengths to create corresponding fluorescent emission lines in the visible or infrared wavelengths. Herein, we present the preliminary results based on the fluorescence spectroscopic studies carried out on the fabricated rare earth doped waveguides. The effect of different rare earth concentrations and excitation wavelengths on the fluorescence intensity were investigated.
A novel fluorescent security label has been produced that could replace numerous conventional fluorescent dyes in document security. This label utilizes rare earth ions doped in a borosilicate glass matrix to produce sharp spectral fluorescence peaks with characteristic long lifetimes due to the rare earth ions. These are subsequently detected by an online detection system based on fluorescence and the long lifetimes to avoid any interference from other fluorophores present in the background. Security is further enhanced by the interaction of the rare earth ions with each other and the effect of the host on the emission spectra and therefore the number of permutations that could be produced. This creates a very secure label with various applications for the security market.