Rapid and precise large area mapping of rare-earth doping homogeneity in luminescent materials

Abstract Doping of luminescent materials by rare-earth (RE) ions is a common practice to achieve desired emission properties in a broad spectral range for large variety of applications including lasers, light emitting diodes, scintillators, quantum technologies, thermoluminescence dosimetry, biomedical/theranostic platforms, etc. As several rare-earths ions are frequently combined, it is subsequently difficult to effectively detect and control their homogeneous distribution within the host material. In this work, the simple, rapid, large scale and precise method of RE mapping using the commercial UV-Vis scanner is presented on the example of Gd/Ce-doped YAG/LuAG single crystals with inhomogeneous RE distribution. Moreover, the influence of RE distribution on the physical, optical and luminescent properties is discussed, with no observable qualitative effect on photoluminescent emission, luminescence decay kinetic and moreover to optical anisotropy. In contrary, RE rich areas exhibit significantly higher values of refractive index, Faraday rotation as well as optical absorption and observed parameter changes precisely followed the RE distribution borders identified by commercial scanner device. Presented method thus provides accurate information about the RE distribution in the material volume in high resolution (≈20 μm) compared to other techniques and thus offers simple, cheap and precise tool for the RE ions mapping in transparent materials.