Development of Glass Phosphor against Anti-Crone Ceramics

Multi-modal artifact metrics as an anti-counterfeiting technique is created based on the concept of multi-modal biometrics. Giving two or more characteristic information to the artifact can improve the certainty of authenticity and increase counterfeiting difficulty. This study aims to develop a glass phosphor that gives two optical feature information, i.e., distribution of emission spectrum and emission intensity, to ceramic products. This phosphor emits visible and near-infrared light through optical excitation and wavelength of near-infrared light. It also demonstrates different distribution of emission spectrum and emission intensity at each observation point on the material. By welding a small amount of phosphor powder onto the ceramic surface, the authenticity and difficulty of counterfeiting could be enhanced in comparison with the existing method we proposed. In our previous study, the abovementioned phosphor was developed by adding two types of rare earth oxides. However, it was not transparent and was yellow in color. Herein, we introduce a new glass phosphor which is transparent and pale in color, and achieves high emission intensity by changing the composition of the base glass material.