Mechanism for broadening and enhancing Nd ³⁺ emission in zinc aluminophosphate laser glass by addition of Bi ₂ O ₃

Abstract

Abstract Nd 3+ ‐doped phosphate laser glasses have been attracting much attention and widespread investigation due to their high solubility of rare earth ( RE ) ions, excellent spectroscopic properties, and large damage threshold. However, the narrow NIR emission bandwidth (less than 30 nm) of these Nd 3+ ‐doped phosphate glasses limits their further application toward ultrahigh power field and efficient fiber laser in new region. Here, we demonstrate the broadening and enhancing of Nd 3+ NIR emission in laser glass of zinc aluminophosphate through tuning the glass structure and covalency of Nd‐O bond without limiting the radiative properties of Nd 3+ . The maximum bandwidth of 1.05 μm emission is broadened to 50 nm, which is comparable to that of Nd 3+ ‐doped aluminate laser glasses. Simultaneously, the lifetime of 4 F 3/2 level is elongated nearly by two times. Structural and optical properties of prepared glasses were discussed systematically to reveal the mechanism. Detailed analysis on optical spectra and glass structure indicates that the bandwidth is affected by not only the covalency of Nd‐O but also the compactness of glass structure. Our results could enrich our understanding about the relationship between local glass structure and luminescence behaviors of active centers, and may be helpful in designing new RE ‐doped laser glass systems.