Crystal growth and the enhanced 1.55 μm fluorescence emission in Ce3+, Yb3+, Er3+ Co-doped KBaCaY(MoO4)3 laser crystal

1.55 mu m laser technology has been widely applied in many fields such as military, information and communications, and biomedical. With the continuous progress in these fields, the demand for new 1.55 mu m laser gain media has become stronger. However, the small non-radiative transition probability and long fluorescence lifetime between the I-4(11/2) and I-4(13/2) energy levels of Er3+ ions lead to up-conversion loss, which in turn reduces the luminescence efficiency in the 1.55 mu m band. To address this problem, this paper introduces a novel Yb3+, Er3+ and Ce3+ co-doped KBa0.94Ca0.06Y(MoO4)(3) crystal and explores the relationship between its structure and spectral properties. By doping Ce3+ ions, the non-radiative transition probability between the I-4(11/2) and I-4(13/2) energy levels of Er3+ ions is effectively increased, which significantly enhances the emission intensity of Er3+ ions in the 1.55 mu m band. Meanwhile, the near-infrared luminescence mechanism of Er3+ ions and its complex competition with up-conversion and mid-infrared luminescence are elaborated in detail. In addition, the doping of Ce3+ ions also significantly enhances the energy transfer efficiency between Yb and Er, from 39.6 % to 94 %. At a Ce3+ ion concentration of 4 mol%, the crystals exhibit optimal emission intensities, indicating their great potential as laser gain media. The research presented here not only provides a comprehensive analysis of the spectral properties of the new laser gain material but also contributes to the advancement of all-solid-state laser gain media suitable for the 1.5 mu m spectral range.