UV, visible and IR active media based on scheelite-type and colquiriite-type fluoride crystals Vadim Semashko, Alexander Naumov, Alexey Nizamutdinov, Stella Korableva, Michail Marisov and Alexey Shavelev EPJ Web Conf., 220 (2019) 01011 Published online: 25 October 2019 DOI: 10.1051/epjconf/201922001011