Spectroscopic investigation of Er 3+-doped (Gd 0.7Y 0.3) 2SiO 5 single crystal for potential application in 1.5 μm laser

Abstract

The Er 3+:(Gd 0.7Y 0.3) 2SiO 5 (hereafter abbreviated as Er 3+:G 0.7Y 0.3SO) single crystals were grown by the Czochralski technique. The unpolarized absorption spectrum and photoluminescence (PL) spectra were measured at room temperature. The Judd–Ofelt phenomenological method was used to estimate the intensity parameters, radiative lifetimes and branching ratios of luminescence. The stimulated emission cross-section of the 4I 13/2 → 4I 15/2 transition of special interest of ∼1.5 μm laser was calculated by the Fuchtbauer–Ladenburg equation, and the relevant gain cross-sections were also estimated for several inverse-population parameters to evaluate a potential laser activity of the Er 3+:G 0.7Y 0.3SO system. Also, the potential range of the optical pumping was assessed based on the absorption cross-section at room temperature. Finally the excited state dynamics of the Er 3+:G 0.7Y 0.3SO system was investigated and experimental lifetimes of 4I 13/2 and 4I 11/2 levels were measured. Taking into account the satisfactory absorption near 971 and 1529 nm, and the high gain cross-section in the range of 1530–1620 nm, the Er 3+:G 0.7Y 0.3SO crystal can be considered as a promising active material for laser operation near 1.5 μm.