Up-Converting Phosphors

Up-converting phosphors have become known as a “taggant” technology. They are a well understood class of materials with many published papers and manufacturers around the world. As a result, they are relatively easy to replicate or mimic. In combination with other taggant technologies, they can be utilized as a step in a multi-level security solution. Microtrace does not recommend up-converting phosphor as a standalone security solution.

Up-converting phosphors are microscopic ceramic powders that convert invisible infrared light wavelengths to visible colored light. There is an anti-stokes shift that separates emission peaks from the infrared excitation source. Essentially, these taggants light up when hit with an infrared light. Microtrace’s up-converting phosphors can emit visible green, red, orange or blue colors when triggered with an infrared laser pen.