Excellent luminescence performance of Ho3+ ions based on a new system of oxyhalide glass

Ho ³⁺ ion has attracted attention owing to its rich energy level structures and ability to emit emissions covering from visible to mid-infrared region. However, finding a suitable host of solid luminescence matrix material for its luminescence is a huge challenge at present. In this paper, a new system of oxyhalide glass based on tellurite-germanate and modified with MgCl ₂ is investigated. It is worth mentioning that through the mixed structural design, the thermal properties of the matrix are further optimized, and the symmetries of the coordination structure near Ho ³⁺ are broken, thus making a great contribution to improving Ho ³⁺ 2–3 μm luminescence, with more than 4-fold increase in fluorescence intensities, and long fluorescence lifetime of 1.24 ms for Ho ³⁺: ⁵I ₇ level. The combined experimental characterizations and theoretical calculations confirm that oxyhalide glass is a very advantageous matrix material, which provides more possibilities for the application of Ho ³⁺ in MIR lasers.