Temperature dependence of the spectroscopic properties of Er:Yb:YAl3(BO3)4 crystal between 300–800 K

Abstract

Er3+/Yb3+ co-doped crystal operates at an elevated temperature during 1.55 μm laser oscillation because a large amount of pump power is converted to heat. The σ-polarized absorption spectra around 976 nm, σ-polarized fluorescence spectra around 1.55 μm, and the fluorescence decay curves of the 4I13/2 multiplet of a c-cut Er:Yb:YAl3(BO3)4 crystal were measured and analyzed at temperatures between 300–800 K. When the temperature was increased from 300 to 800 K, the σ-polarized absorption cross-section at 976 nm, σ-polarized stimulated emission cross-section at 1523 nm, and fluorescence lifetime of the 4I13/2 multiplet decreased from 2.67×10−20 cm2, 1.51×10−20 cm2, and 330 μs to 1.26×10−20 cm2, 0.73×10−20 cm2, and 247 μs, respectively, while the full width at half the maximum of the absorption band around 976 nm increased from 18 to 35 nm. The results demonstrate that the 1.55 μm laser performance of the crystal may change strongly with the temperature in the crystal.