EuF2-based crystals as media for high-power mid-infrared Faraday isolators

This letter presents the investigation of spectral, magneto-optical and thermo-optical characteristics of cubic EuF2+x solid solution crystals. The dispersion of the Verdet constant measured in the wavelength range of 532-1940 nm demonstrates that such crystals can be used for creating Faraday isolators for the wavelength of similar to 2 mu m. The optical anisotropy parameter of EuF2+x crystals is negative, which means that there exists a dedicated orientation of the crystallographic axes at which thermally induced depolarization may be reduced substantially. The performed research shows that an EuF2 crystal is highly promising for the development of Faraday isolators for high-power mid-IR lasers. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.