Prof. Przemysław J. Dereń received a PhD in physics from the Institute of Low Temperature and Structure Research, PAS. Subsequently, he spent his postdoctoral fellowship at the University of Bern, at CNRS Meudon Bellevue, and at L'Institut de Physique Nucléaire d'Orsay. In the years 1999–2008, he worked as a visiting professor at Blaise Pascal University in Clermont Ferrand. Since 2015, he has been a professor at the ILT&SR PAS in Wrocław, where he is leading the Optical Spectroscopy Department. His research interests are phosphors for WLED, perovskites, laser materials, transparent ceramics, and spectroscopy of rare-earth and transition metal ions. https://orcid.org/0000-0001-6316-6954.