Controllable and directional growth of Er:Lu2O3 single crystal by edge-defined film-fed technique

The sesquioxide Lu2O3 single crystal has enormous potential applications as host materials for solid-state lasers operating at high average powers, and its development is limited by lack of large size single crystals with high quality. Compared with traditional Czochralski (Cz) method, edge-defined film-fed growth (EFG) method, employing a die or a shaper, doesn’t contact with the melt directly during the growth process. Therefore, the growth interface is stable and the serious bottleneck problems of “w”-shaped isotherm in Czochralski method could be avoided effectively. Herein, the EFG method may be a promising technique to obtain ultra-high temperature sesquioxides single crystals with large size, more importantly high quality. Accordingly, the sesquioxide Lu2O3 single crystal has been grown controllably with an oriented seed by EFG method for the first time and the EFG method is promoted to an extremely high temperature of 2450 °C. The dimension of the grown crystal is Φ 25×30 mm3, and the difficulties encountered during the crystal growth have been discussed in detail. Furthermore, the quality of the crystal has been evaluated. The optical properties of the as-grown crystal have been investigated.