Growth and Spectral Properties of Er3+ and Yb3+ Co-Doped Bismuth Silicate Single Crystal

Rare-earth-doped bismuth silicate (Bi4Si3O12, BSO) crystal is a multifunctional material for scintillation, LED, and laser applications. In the present study, Er3+ and Yb3+ ions co-doped bismuth silicate crystals were grown by a modified vertical Bridgman method, and their spectral properties were investigated for the first time. Transparent Er/Yb: BSO single crystal up to phi 25 mm x 30 mm was obtained. The segregation coefficient of the Er/Yb: BSO crystal was measured to be 0.96 for Er3+ ions and 0.91 for Yb3+ ions. Absorption and fluorescence spectra had been recorded in the range of 200-1700 nm. The absorption cross section was calculated to be 6.96 x 10(-20) cm(2) at 976 nm with the full width at half maximum (FWHM) of 8 nm, and the emission cross section was 0.9771 x 10(-20) cm(2) at 1543 nm with FWHM of 16 nm. The fluorescence decay curve was measured at 976 nm excitation. By linear fitting, the fluorescence lifetime of the upper I-4(13/2) level of Er3+ was 8.464 ms at room temperature. Compared with Er-3(+) ion-doped bismuth silicate crystal (Er: BSO), the Er/Yb: BSO crystal has a wider FWHM and larger absorption cross section. The results indicate that the Er/Yb: BSO crystal is a potential lasing crystal.