来源：ACS Publications
Bismuth-doped rare earth iron garnet (Bi:RIG) is a promising magneto-optical material for use in 1310 nm optical isolators. The top-seeded solution growth (TSSG) method has advantages for growing high-quality crystals. However, the Bi concentration in the bulk iron garnet crystal grown by this method is low, leading to a small specific Faraday rotation angle (θF). To increase θF in the Bi:RIG crystal in this paper, a large ion radius of Nd3+ would be introduced into the RIG garnet crystal to expand the unit cell and enhance the Bi3+ concentration. Thus, high-quality and heavily Bi3+-doped Nd,Bi:(HoEu)IG crystals were successfully grown by using the TSSG method. The saturation magnetization, Curie temperature, and specific Faraday rotation angle of the Nd,Bi:(HoEu)IG crystals are positively correlated with the concentrations of Bi3+ and Nd3+. As a result, the (Nd0.5Bi1.2Ho0.8Eu0.2Gd0.3)(Fe4.5Ga0.5)O12 crystal exhibits a high θF of −1320 deg cm–1 in a low saturated applied magnetic field of 60 mT and a high transmittance of 70.5% at 1310 nm. The θF of this crystal is twice that of the Nd-undoped (Bi0.8Ho1.2Eu0.8Gd0.2)(Fe4.9Ga0.1)O12 crystal and 1.1 times that of a commercial Bi:(HoEu)IG crystal grown by using liquid-phase epitaxy technology. Therefore, the (Nd0.5Bi1.2Ho0.8Eu0.2Gd0.3)(Fe4.5Ga0.5)O12 crystal shows considerable promise for application in 1310 nm optical isolators due to its excellent magneto-optical properties.