EPR and optical study of Fe in Nd:YAlO3 laser crystals

Abstract
EPR data confirm the presence of Fe impurities in single‐crystal laser hosts of YAlO3. Optical absorption in Fe:YAlO3 was measured to distinguish contributions of Fe3+ and Fe2+ to passive loss in Nd:YAlO3. YAlO3 crystals grown or annealed in H2 contain both Fe2+ and OH which increase the absorption loss at 1.06 μm and cause fluorescence quenching.