1. Laboratory of High‐purity Optical MaterialsG.G. Devyatykh Institute of Chemistry of High-Purity Substances RAS 49 Tropinin Str. Nizhny Novgorod 603137 Russia
2. Department of Diagnosis of Optical Materials for Advanced LasersFederal Research CenterThe Institute of Applied Physics RAS 46 Ulyanov Str. Nizhny Novgorod 603155 Russia
3. Advanced School of General and Applied PhysicsLobachevsky State University of Nizhny Novgorod 23 Gagarin Ave. Nizhny Novgorod 603022 Russia