Ytterbium and Erbium Co-doped rare-earth aluminum borate crystals as new materials for eye-safe lasers: Flux growth and characterization

Abstract

Phase relationships in RAl3(BO3)4-(K2Mo3O10-R2O3-B2O3) pseudo-quaternary systems (R = Y, Gd, Er, Yb, Lu) have been studied in the temperature range from 1150°C to 900 °C, and the results obtained for 25-17 wt.% RAl3(BO3)4 (RAB) concentrations were presented graphically as their projections onto the cross section at 900 °C of temperature-composition diagram. Er,Yb co-doped single crystals were grown on dipped "point" seeds. The absorption spectra of (Er,Yb):RAB crystals were measured at room temperature. The optical and emission spectrum and lifetime of the 4I13/2 energy level were determined. From the spectroscopic point of view, Er-Yb co-doped RAB material looks promising as a gain medium for compact diode-pumped lasers operating in the 1500-1600 nm eye-safe spectral range.