Growth and red-orange emission of Sm3+ doped SrAl12O19 single crystals

Abstract

Sm:SrAl12O19 (Sm:SRA) single crystals with dopant concentration of 1 and 8 at.% have been successfully grown by the Czochralski method. Polarized absorption spectra, emission spectra, as well as the lifetime measurements were performed. The absorption cross-section was calculated to be 1.97 × 10−20 cm2 at 404 nm for σ polarization and 1.13 × 10−20 cm2 at 405 nm for π polarization, respectively. The highest emission cross-section at 593 nm was calculated to be 0.58 × 10−21 cm2 for σ polarization and 0.45 × 10−21 cm2 for π polarization, with full width at half maximum (FWHM) of 7.73 nm and 7.42 nm, respectively. Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6) and radiative properties for the important luminescent level of Sm3+ ions were derived by using the polarized absorption spectra of 8 at.% Sm:SrAl12O19. The fluorescence lifetime of 1 at.% and 8 at.% Sm:SrAl12O19 crystals were calculated to be 2.83 ms and 2.11 ms, respectively. The results indicate that the Sm:SRA crystal would be potential laser material for red-orange oscillation pumped by commercially 405 nm laser diode.