February 6, 2025, 4:00pm- Rare-earth doped and undoped solid-state materials for photonic applications

 Nowadays, research on new types of advanced optical materials for high-tech applications, especially in photonics and optics, is still a part of cutting-edge research in material science. As an example, one can mention the development of inorganic crystals for scintillators and radiation detectors, medical imaging, solid state or fiber lasers or light emitting diodes and quantum information processing. In-dept spectroscopic analysis of luminescent properties of RE-doped materials accompanied by a rapid and precise detection of luminescence/optically active impurities or/and dopant distribution is therefore crucial step not only in scientific research, but in material fabrication and qualitative control as the non-uniformity of distribution is a limitation for majority of application.

 Regarding the spectroscopic characterization, the Judd-Ofelt (JO) theory, introduced by B.R. Judd and G.S. Ofelt in 1962, has been pivotal in rare-earth optical spectroscopy for over six decades, describing intra 4f->4f electronic transitions with three intensity JO parameters. However, like any technique, both theoretical and experimental limitations arise at certain points. These constraints will be examined using the example of doped amorphous materials, specifically Er³⁺-doped tellurite glasses, through the newly introduced Combinatorial Judd-Ofelt analysis and the LOMS.cz (Luminescence, Optics, and Magneto-Optics Software) online computational tool.

 In contrary, for industrial applications, it is necessary to look for simple approaches to perform fast qualitative and quantitative optical analysis of prepared materials such as synthetic YAG and LuAG garnets doped with optically active trivalent rare-earth ions (such as Ce³⁺ and Gd³⁺ ions). However, majority of commonly used experimental techniques, such as Uv-Vis-NIR spectroscopy, spectroscopic ellipsometry, EDX, etc, which are standards in laboratory environment, do not provide wide field, fast and high throughput inspection tool applicable for industry requirements. Therefore, a novel and straightforward approach for rapid, large-area mapping of rare-earth doping homogeneity is introduced, utilizing a commercial UV-Vis scanner, and compared with other above-mentioned methods. This method is then suitable for both laboratory research and industrial applications.